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Frontiers in Immunology logoLink to Frontiers in Immunology
. 2014 Apr 22;5:162. doi: 10.3389/fimmu.2014.00162

Primary Immunodeficiency Diseases: An Update on the Classification from the International Union of Immunological Societies Expert Committee for Primary Immunodeficiency

Waleed Al-Herz 1,2, Aziz Bousfiha 3, Jean-Laurent Casanova 4,5, Talal Chatila 6, Mary Ellen Conley 4, Charlotte Cunningham-Rundles 7, Amos Etzioni 8, Jose Luis Franco 9, H Bobby Gaspar 10,*, Steven M Holland 11, Christoph Klein 12, Shigeaki Nonoyama 13, Hans D Ochs 14, Erik Oksenhendler 15,16, Capucine Picard 5,17, Jennifer M Puck 18, Kate Sullivan 19, Mimi L K Tang 20,21,22
PMCID: PMC4001072  PMID: 24795713

Abstract

We report the updated classification of primary immunodeficiencies (PIDs) compiled by the Expert Committee of the International Union of Immunological Societies. In comparison to the previous version, more than 30 new gene defects are reported in this updated version. In addition, we have added a table of acquired defects that are phenocopies of PIDs. For each disorder, the key clinical and laboratory features are provided. This classification is the most up-to-date catalog of all known PIDs and acts as a current reference of the knowledge of these conditions and is an important aid for the molecular diagnosis of patients with these rare diseases.

Keywords: primary immunodeficiencies, IUIS, classification, genetic defects, genotype

Background

The International Union of Immunological Societies (IUIS) Expert Committee on Primary Immunodeficiency met in New York on 19th–21st April 2013 to update the classification of human primary immunodeficiencies (PIDs). This report represents the most current and complete catalog of known PIDs. It serves as a reference for these conditions and provides a framework to help in the diagnostic approach to patients suspected to have PID.

As in previous reports, we have classified the conditions into major groups of PIDs and these are now represented in nine different tables. In each table, we list the condition, its genetic defect if known, and the major immunological and in some conditions the non-immunological abnormalities associated with the disease. The classification this year differs slightly from the previous edition in that Table 1 lists combined immunodeficiencies without non-immunologic phenotypes, whereas Table 2 refers to combined immunodeficiencies with syndromic features, as increasing numbers of these are being identified. The title and classification of Tables 38 present the same major PID groups as in the previous report.

Table 1.

Combined immunodeficiencies.

Disease Genetic defect/presumed pathogenesis Inheritance Circulating T cells Circulating B cells Serum Ig Associated features OMIM number
1. TB+ severe combined immunodeficiency (SCID)
(a) γc deficiency Mutation of IL-2RG XL Markedly decreased Normal or increased Decreased Markedly decreased NK cells 300400
Defect in γ chain of receptors for IL-2, -4, -7, -9, -15, -21
(b) JAK3 deficiency Mutation of JAK3 AR Markedly decreased Normal or increased Decreased Markedly decreased NK cells 600173
Defect in Janus-activating kinase 3
(c) IL7Rα deficiency Mutation of IL7RA AR Markedly decreased Normal or increased Decreased Normal NK cells 146661
Defect in IL-7 receptor α chain
(d) CD45 deficiencya Mutation of PTPRC AR Markedly decreased Normal Decreased Normal γ/δ T cells 151460
Defect in CD45
(e) CD3δ deficiency Mutation of CD3D AR Markedly decreased Normal Decreased Normal NK cells 186790
Defect in CD3δ chain of T cell antigen receptor complex No γ/δ T cells
(f) CD3ε deficiencya Mutation of CD3E AR Markedly decreased Normal Decreased Normal NK cells 186830
Defect in CD3ε chain of T cell antigen receptor complex No γ/δ T cells
(g) CD3ζ deficiencya Mutation of CD3Z AR Markedly decreased Normal Decreased Normal NK cells 186740
Defect in CD3ζ chain of T cell antigen receptor complex No γ/δ T cells
(h) Coronin-1A deficiencya Mutation of CORO1A defective thymic egress of T cells and defective T cell locomotion AR Markedly decreased Normal Decreased Detectable thymus EBV associated B cell lymphoproliferation 605000
2. TBSCID
(i) DNA recombination defects
(a) RAG 1 deficiency Mutation of RAG1 AR Markedly decreased Markedly decreased Decreased 601457
Defective VDJ recombination; defect of recombinase activating gene (RAG) 1
(a) RAG 2 deficiency Mutation of RAG2 AR Markedly decreased Markedly decreased Decreased 601457
Defective VDJ recombination; defect of recombinase activating gene (RAG) 2
(b) DCLRE1C (artemis) deficiency Mutation of ARTEMIS AR Markedly decreased Markedly decreased Decreased Radiation sensitivity 602450
Defective VDJ recombination; defect in artemis DNA recombinase repair protein
(c) DNA PKcs deficiencya Mutation of PRKDC- Defective VDJ recombination; defect in DNA PKcs AR Markedly decreased Markedly decreased Decreased Radiation sensitivity, microcephaly, and developmental defects 600899
Recombinase repair protein
(ii) Reticular dysgenesis, AK2 deficiency Mutation of AK2 AR Markedly decreased Decreased or normal Decreased Granulocytopenia and deafness 103020
Defective maturation of lymphoid and myeloid cells (stem cell defect)
Defect in mitochondrial adenylate kinase 2
(iii) Adenosine deaminase (ADA) deficiency Mutation of ADA absent ADA activity, elevated lymphotoxic metabolites (dATP, S-adenosyl homocysteine) AR Absent from birth (null mutations) or progressive decrease Absent from birth of progressive decrease Progressive decrease Decreased NK cells, often with costochondral junction flaring, neurological features, hearing impairment, lung and liver manifestations; partial ADA deficiency may lead to delayed or milder presentation 102700
Combined immunodeficiencies generally less profound than severe combined immunodeficiency
3. CD40 ligand deficiency Mutation of CD40LG defects in CD40 ligand (CD40L; also called TNFSF5 or CD154) cause defective isotype switching and impaired dendritic cell signaling XL Normal; may progressively decrease sIgM+ and sIgD+ B cells present, other surface isotype positive B cells absent IgM increased or normal, other isotypes decreased Neutropenia, thrombocytopenia; hemolytic anemia, biliary tract and liver disease, opportunistic infections 300386
4. CD40 deficiencya Mutation of CD40 (also called TNFRSF5) defects in CD40 cause defective isotype switching and impaired dendritic cell signaling AR Normal IgM+ and IgD+ B cells present, other isotypes absent IgM increased or normal, other isotypes decreased Neutropenia, gastrointestinal and liver/biliary tract disease, opportunistic infections 109535
5. Purine nucleoside phosphorylase (PNP) deficiency Mutation of PNP, absent PNP, and T cell and neurologic defects from elevated toxic metabolites, especially dGTP AR Progressive decrease Normal Normal or decreased Autoimmune hemolytic anemia, neurological impairment 164050
6. CD3γ deficiencya Mutation of CD3G defect in CD3 γ – component of the T cell antigen receptor complex AR Normal, but reduced TCR expression Normal Normal 186740
7. CD8 deficiencya Mutation of CD8A, defects of CD8 α chain – important for maturation and function of CD8 T cells AR Absent CD8, normal CD4 cells Normal Normal 186910
8. ZAP70 deficiency Mutation in ZAP70 intracellular signaling kinase, acts downstream of TCR AR Decreased CD8, normal CD4 cells Normal Normal Autoimmunity in some cases 269840
9. MHC class I deficiency Mutations in TAP1, TAP2, or TAPBP (tapasin) genes giving MHC class I deficiency AR Decreased CD8, normal CD4 Normal Normal Vasculitis; pyoderma gangrenosum 604571
10. MHC class II deficiency Mutation in transcription factors for MHC class II proteins (CIITA, RFX5, RFXAP, RFXANK genes) AR Normal number, decreased CD4 cells Normal Normal or decreased Failure to thrive, diarrhea, respiratory tract infections, liver/biliary tract disease 209920
11. ITK deficiencya Mutations in ITK encoding IL-2-inducible T cell kinase required for TCR-mediated activation AR Progressive decrease Normal Normal or decreased EBV-associated B cell lymphoproliferation, lymphoma 613011
Normal or decreased IgG
12. SH2D1A deficiency (XLP1) Mutations in SH2D1A encoding an adaptor protein regulating intracellular signals XL Normal or increased activated T cells Reduced memory B cells Partially defective NK cell and CTL cytotoxic activity Clinical and immunologic features triggered by EBV infection: HLH, lymphoproliferation, aplastic anemia, lymphoma 308240
Hypogammaglobulinemia
Absent iNKT cells
13. Cartilage hair hypoplasia Mutations in RMRP (RNase MRP RNA) involved in processing of mitochondrial RNA and cell cycle control AR Varies from severely decreased (SCID) to normal; impaired lymphocyte proliferation Normal Normal or reduced. antibodies variably decreased Can present just as combined immunodeficiency without other features of short-limbed dwarfism 250250
Also see Table 2
14. MAGT1 deficiencya Mutations in MAGT1, impaired Mg++ flux leading to impaired TCR signaling XL Decreased CD4 cells reduced numbers of RTE, impaired T cell proliferation in response to CD3 Normal Normal EBV infection, lymphoma; viral infections, respiratory, and GI infections 300715
15. DOCK8 deficiency Mutations in DOCK8 – regulator of intracellular actin reorganization AR Decreased impaired T lymphocyte proliferation Decreased, low CD27+ memory B cells Low IgM, increased IgE Low NK cells with impaired function, hypereosinophilia, recurrent infections; severe atopy, extensive cutaneous viral and bacterial (staph.) infections, susceptibility to cancer 243700
16. RhoH deficiencya Mutations in RHOH – an atypical Rho GTPase transducing signals downstream of various membrane receptors AR Normal Normal Normal HPV infection, lymphoma, lung granulomas, molluscum contagiosum 602037
Low naïve T cells and RTE, restricted T cell repertoire and impaired T cells proliferation in response to CD3 stimulation
17. MST1 deficiency Mutations in STK4 – a serine/threonine kinase AR Decreased/increased proportion of terminal differentiated effector memory cells (TEMRA), low naïve T cells, restricted T cell repertoire in the TEMRA population, and impaired T cells proliferation Decreased High Recurrent bacterial, viral, and candidal infections; intermittent neutropenia; EBV-driven lymphoproliferation; lymphoma; congenital heart disease, autoimmune cytopenias; HPV infection 614868
18. TCRα deficiencya Mutations in TRAC – essential component of the T cell receptor AR Normal all CD3 T cells expressed TCRγδ (or may be better to say: TCRαβ T cell deficiency), impaired T cells proliferation Normal Normal Recurrent viral, bacterial, and fungal infections, immune dysregulation autoimmunity, and diarrhea 615387
19. LCK deficiencya Defects in LCK – a proximal tyrosine kinase that interacts with TCR AR Normal total numbers but CD4+ T cell lymphopenia, low Treg numbers, restricted T cell repertoire, and impaired TCR signaling Normal Normal IgG and IgA and increased IgM Diarrhea, recurrent infections, immune dysregulation autoimmunity 153390
20. MALT1 deficiencya Mutations in MALT1 – a caspase-like cysteine protease that is essential for nuclear factor kappa B activation AR Normal impaired T cells proliferation Normal Normal Bacterial, fungal, and viral infections 604860
Impaired antibody response
21. IL-21R deficiencya Defects in IL-21R – together with common gamma chain binds IL-21 AR Abnormal T cell cytokine production; abnormal T cell proliferation to specific stimuli Normal Normal but impaired specific responses Susceptibility to cryptosporidium and pneumocystis and cholangitis 605383
22. UNC119 deficiencya Defects in UNC119 – an activator of src tyrosine kinases AD Low T cells Mostly low Normal Recurrent bacterial, fungal, and viral infections 604011
CD4+ T cell lymphopenia, impaired TCR signaling
23. CARD11 deficiencya Defects in CARD11 – acts as a scaffold for NF-κB activity in the adaptive immune response AR Normal predominance of naive T lymphocyte, impaired T cells proliferation Normal predominance of transitional B lymphocytes Absent/low Pneumocystis jiroveci pneumonia, bacterial infections 615206
24. OX40 deficiencya Defects in OX40 – a co-stimulatory molecule expressed on activated T cells AR Normal T cell numbers Normal B cell numbers Normal Kaposi’s sarcoma; impaired immunity to HHV8 615593
Low levels of antigen-specific memory CD4+ cells Lower frequency of memory B cells
25. IKBKB deficiencya Defects in IKBKB – encodes IkB kinase 2 a component of the NF-κB pathway AR Normal total T cells; absent regulatory and gd T cells; impaired TCR activation Normal B cell numbers; impaired BCR activation Decreased Recurrent bacterial, viral, and fungal infections; clinical phenotype of SCID 615592
26. Activated PI3K-δ Mutation in PIK3CD, PI3K-δ AD gain-of-function Decreased total numbers of T cells Decreased total peripheral B cell and switched memory B cells; increased transitional B cells Reduced IgG2 and impaired antibody to pneumococci and hemophilus Respiratory infections, bronchiectasis; autoimmunity; chronic EBV, and CMV infection 602839
27. LRBA deficiency Mutations in LRBA (lipopolysaccharide responsive beige-like anchor protein) AR Normal or decreased CD4 numbers; T cell dysregulation Low or normal numbers of B cells Reduced I IgG and IgA in most Recurrent infections, inflammatory bowel disease, autoimmunity; EBV infections 606453
28. CD27 deficiencya Mutations in CD27, encoding TNF-R member superfamily required for generation and long-term maintenance of T cell immunity AR Normal No memory B cells Hypogamma globulinemia following EBV infection Clinical and immunologic features triggered by EBV infection, HLH 615122
Aplastic anemia, lymphoma
Hypogammaglobulinemia
Low iNKT cells
29. Omenn syndrome Hypomorphic mutations in RAG1, RAG2, artemis, IL7RA, RMRP, ADA, DNA ligase IV, IL-2RG, AK2, or associated with DiGeorge syndrome; some cases have no defined gene mutation Present; restricted T cell repertoire, and impaired function Normal or decreased Decreased, except increased IgE Erythroderma, eosinophilia, adenopathies, hepatosplenomegaly 603554

XL, X-linked inheritance; AR, autosomal recessive inheritance; AD, autosomal dominant inheritance; SCID, severe combined immune deficiencies; EBV, Epstein–Barr virus; Ca++, calcium; MHC, major histocompatibility complex, RTE, recent thymic emigrants, HPV, human papillomavirus.

aTen or fewer unrelated cases reported in the literature.

Infants with SCID who have maternal T cells engraftment may have T cells that do not function normally; these cells may cause autoimmune cytopenias or graft versus host disease. Hypomorphic mutations in several of the genes that cause SCID may result in Omenn syndrome (OS), or “leaky” SCID or a less profound CID phenotype. Both OS and leaky SCID can be associated with higher numbers of T cells and reduced rather than absent activation responses when compared with typical SCID caused by null mutations. A spectrum of clinical findings including typical SCID, OS, leaky SCID, granulomas with T lymphopenia, autoimmunity, and CD4+ T lymphopenia can be found with RAG gene defects. RAC2 deficiency is a disorder of leukocyte motility and is reported in Table 5; however, one patient with RAC2 deficiency was found to have absent T cell receptor excision circles (TRECs) by newborn screening, but T cell numbers and mitogen responses were not impaired. For additional syndromic conditions with T cell lymphopenia, such as DNA repair defects, cartilage hair hypoplasia, IKAROS deficiency, and NEMO syndrome, see Tables 2 and 6; however, it should be noted that individuals with the most severe manifestations of these disorders could have clinical signs and symptoms of SCID. Severe folate deficiency (such as with malabsorption due to defects in folate carrier or transporter genes SLC10A1 or PCFT) and some metabolic disorders, such as methylmalonic aciduria, may present with reversible profound lymphopenia in addition to their characteristic presenting features.

Table 2.

Combined immunodeficiencies with associated or syndromic features.

Disease Genetic defect/presumed pathogenesis Inheritance Circulating T cells Circulating B cells Serum Ig Associated features OMIM number
1. Congenital thrombocytopenia
(a) Wiskott– Aldrich syndrome (WAS) Mutations in WAS; cytoskeletal, and immunologic synapse defect affecting hematopoietic stem cell derivatives XL Progressive decrease, abnormal lymphocyte responses to anti-CD3 Normal Decreased IgM: antibody to polysaccharides particularly decreased; often increased IgA and IgE Thrombocytopenia with small platelets; eczema; lymphoma; autoimmune disease; IgA nephropathy; bacterial and viral infections. XL thrombocytopenia is a mild form of WAS, and XL neutropenia is caused by missense mutations in the GTPase binding domain of WASP 301000
(b) WIP deficiencya Mutations in WIPF1; cytoskeletal and immunologic synapse defect affecting hematopoietic stem cell derivatives AR Reduced, defective lymphocyte responses to anti-CD3 Low Normal, except for increased IgE Recurrent infections; eczema; thrombocytopenia. WAS-like phenotype 614493
2. DNA repair defects (other than those in Table 1)
(a) Ataxia–telangiectasia Mutations in ATM; disorder of cell cycle checkpoint; and DNA double-strand break repair AR Progressive decrease Normal Often decreased IgA, IgE, and IgG subclasses; increased IgM monomers; antibodies variably decreased Ataxia; telangiectasia; pulmonary infections; lymphoreticular and other malignancies; increased alpha fetoprotein and increased radiosensitivity; chromosomal instability 208900
(b) Ataxia–telangiectasia-like disease (ATLD)a Hypomorphic mutations in MRE11; disorder of cell cycle checkpoint and DNA double-strand break repair AR Progressive decrease Normal Antibodies variably decreased Moderate ataxia; pulmonary infections; severely increased radiosensitivity 604391
(c) Nijmegen breakage syndrome Hypomorphic mutations in NBS1 (Nibrin); disorder of cell cycle checkpoint and DNA double-strand break repair AR Progressive decrease Variably reduced Often decreased IgA, IgE, and IgG subclasses; increased IgM; antibodies variably decreased Microcephaly; bird-like face; lymphomas; solid tumors; increased radiosensitivity; chromosomal instability 251260
(d) Bloom syndrome Mutations in BLM; RecQ-like helicase AR Normal Normal Reduced Short stature; bird-like face; sun-sensitive erythema; marrow failure; leukemia; lymphoma; chromosomal instability 210900
(e) Immunodeficiency with centromeric instability and facial anomalies (ICF) Mutations in DNA methyltransferase DNMT3B (ICF1) resulting in defective DNA methylation AR Decreased or normal; responses to PHA may be decreased Decreased or normal Hypogamma globulinemia; variable antibody deficiency Facial dysmorphic features; macroglossia; bacterial/opportunistic infections; malabsorption; cytopenias; malignancies; multiradial configurations of chromosomes 1, 9, 16; no DNA breaks 242860
(f) Immunodeficiency with centromeric instability and facial anomalies (ICF) Mutations in ZBTB24 (ICF2) AR Decreased or normal; responses to PHA may be decreased Decreased or normal Hypogamma globulinemia; variable antibody deficiency Facial dysmorphic features; macroglossia; bacterial/opportunistic infections; malabsorption; cytopenias; malignancies; multiradial configurations of chromosomes 1, 9, 16 242860
(g) PMS2 deficiency Mutations in PMS2, resulting in class switch recombination deficiency due to impaired mismatch repair AR Normal Switched and non-switched B cells are reduced Low IgG and IgA, elevated IgM, abnormal antibody responses Recurrent infections; café-au-lait spots; lymphoma, colorectal carcinoma, brain tumor 600259
(h) RNF168 deficiencya Mutations in RNF168, resulting in defective DNA double-strand break repair AR Normal Normal Low IgG or low IgA Short stature; mild motor control to ataxia and normal intelligence to learning difficulties; mild facial dysmorphism to microcephaly; increased radiosensitivity 611943
(i) MCM4 deficiency Mutations in MCM4 (minichromosome maintenance complex component 4) gene involved in DNA replication and repair AR Normal Normal Normal Viral infections (EBV, HSV, VZV) Adrenal failure Short stature 609981
3. Thymic defects with additional congenital anomalies
(a) DiGeorge anomaly Contiguous gene defect in 90% affecting thymic development; may also be due to heterozygous mutation in TBX1 (chromosome 22q11.2 deletion or TBX1 haploinsufficient syndrome) De novo defect (majority) or AD Decreased or normal; 5% have <1500 CD3 T cells/μL Normal Normal or decreased Hypoparathyroidism, conotruncal malformation; abnormal facies; large deletion (3 Mb) in 22q11.2 (or rarely a deletion in 10p) 188400
(b) CHARGE syndrome Variable defects of the thymus and associated T cell abnormalities often due to deletions or mutations in CHD7, SEMA3E, or as yet unknown genes De novo defect (majority) or AD Decreased or normal; some have <1500 CD3 T cells/μL Normal Normal or decreased Coloboma, heart anomaly, choanal atresia, retardation, genital and ear anomalies 214800 608892
4. Immune-osseous dysplasias
(a) Cartilage hair hypoplasia Mutations in RMRP (RNase MRP RNA) involved in processing of mitochondrial RNA and cell cycle control AR Varies from severely decreased (SCID) to normal; impaired lymphocyte proliferation Normal Normal or reduced. Antibodies variably decreased Short-limbed dwarfism with metaphyseal dysostosis, sparse hair, bone marrow failure, autoimmunity, susceptibility to lymphoma and other cancers, impaired spermatogenesis, neuronal dysplasia of the intestine 250250
(b) Schimke syndrome Mutations in SMARCAL1 involved in chromatin remodeling AR Decreased Normal Normal Short stature, spondiloepiphyseal dysplasia, intrauterine growth retardation, nephropathy; bacterial, viral, and fungal infections; may present as SCID; bone marrow failure 242900
5. Hyper-IgE syndromes (HIES)
(a) AD-HIES (Job’s syndrome) Dominant-negative heterozygous mutations in STAT3 AD Often de novo defect Normal Th-17 and T follicular helper cells decreased Normal Switched and non-switched memory B cells are reduced; BAFF level increased Elevated IgE; specific antibody production decreased Distinctive facial features (broad nasal bridge), eczema, osteoporosis, and fractures, scoliosis, delay of shedding primary teeth, hyperextensible joints, bacterial infections (skin and pulmonary abscesses, pneumatoceles) due to Staphylococcus aureus, candidiasis, aneurysm formation 147060
(i) Tyk2 deficiencya Mutation in TYK2 AR Normal, but multiple cytokine signaling defect Normal (±) Elevated IgE Susceptibility to intracellular bacteria (Mycobacteria, Salmonella), fungi, and viruses 611521
(ii) DOCK8 deficiency Mutations in DOCK8 – regulator of intracellular actin reorganization AR Decreased impaired T lymphocyte proliferation Decreased, low CD27+ memory B cells Low IgM, increased IgE Low NK cells with impaired function, hypereosinophilia, recurrent infections; severe atopy, extensive cutaneous viral and bacterial (staph.) infections, susceptibility to cancer 243700
6. Dyskeratosis congenital (DKC)
(a) XL-DKC Mutations in dyskerin (DKC1) (Hoyeraal–Hreidarsson syndrome) XL Progressive decrease Progressive decrease Variable Intrauterine growth retardation, microcephaly, nail dystrophy, recurrent infections, digestive tract involvement, pancytopenia, reduced number and function of NK cells 305000
(b) AR-DKC due to NHP2 deficiency Mutation in NOLA2 (NHP2) AR Decreased Variable Variable Pancytopenia, sparse scalp hair and eyelashes, prominent periorbital telangiectasia, and hypoplastic/dysplastic nails 613987
(c) AR-DKC due to NOP10 deficiency Mutation in NOLA3 (NOP10 PCFT) AR Decreased Variable Variable Pancytopenia, sparse scalp hair and eyelashes, prominent periorbital telangiectasia, and hypoplastic/dysplastic nails 224230
(d) AR-DKC due to RTEL1 deficiency Mutation in (RTEL1) AR Decreased Variable Variable Pancytopenia, sparse scalp hair and eyelashes, prominent periorbital telangiectasia, and hypoplastic/dysplastic nails 608833
(e) AD-DKC due to TERC deficiency Mutation in TERC AD Variable Variable Variable Reticular hyperpigmentation of the skin, dystrophic nails, osteoporosis premalignant leukokeratosis of the mouth mucosa, palmar hyperkeratosis, anemia, pancytopenia 127550
(f) AD-DKC due to TERT deficiency Mutation in TERT AD Variable Variable Variable Reticular hyperpigmentation of the skin, dystrophic nails, osteoporosis premalignant leukokeratosis of the mouth mucosa, palmar hyperkeratosis, anemia, pancytopenia 614742
(g) AD-DKC due to TINF2 deficiency Mutation in TINF2 AD Variable Variable Variable Reticular hyperpigmentation of the skin, dystrophic nails, osteoporosis premalignant leukokeratosis of the mouth mucosa, palmar hyperkeratosis, anemia, pancytopenia 613990
7. Defects of vitamin B12 and folate metabolism
(a) TCN2 deficiency Mutation in TCN2; encodes transcobalamin, a transporter of cobalamin into blood cells AR Normal Variable Decreased Megaloblastic anemia, pancytopenia, untreated for prolonged periods results in mental retardation 275350
(b) SLC46A1 deficiency Mutation in SLC46A1; a proton coupled folate transporter AR Variable numbers and activation profile Variable Decreased Megaloblastic anemia, failure to thrive untreated for prolonged periods results in mental retardation 229050
(c) MTHFD1a deficiency Mutations in MTHFD1; essential for processing of single-carbon folate derivatives AR Low Low Decreased Megaloblastic anemia, failure to thrive neutropenia, seizures, mental retardation
8. Comel–Netherton syndrome Mutations in SPINK5 resulting in lack of the serine protease inhibitor LEKTI, expressed in epithelial cells AR Normal Switched and non-switched B cells are reduced Elevated IgE and IgA Congenital ichthyosis, bamboo hair, atopic diathesis, increased bacterial infections, failure to thrive 256500
Antibody variably decreased
9. Winged helix deficiency (Nude)a Defects in forkhead box N1 transcription factor encoded by FOXN1 AR Markedly decreased Normal Decreased Alopecia, abnormal thymic epithelium, impaired T cell maturation 600838
10. ORAI-I deficiencya Mutation in ORAI1, a Ca++ release-activated channel (CRAC) modulatory component AR Normal number, but defective TCR-mediated activation Normal Normal Autoimmunity, anhydrotic ectodermic dysplasia, non-progressive myopathy defective TCR-mediated activation 610277
11. STIM1 deficiencya Mutations in STIM1, a stromal interaction molecule 1 AR Normal number, but defective TCR-mediated activation Normal Normal Autoimmunity, anhydrotic ectodermal dysplasia, non-progressive myopathy defective TCR-mediated activation 605921
12. STAT5b deficiencya Mutations in STAT5B, signal transducer, and transcription factor, essential for normal signaling from IL-2 and 15, key growth factors for T and NK cells AR Modestly decreased Normal Normal Growth-hormone insensitive dwarfism 245590
Dysmorphic features
Eczema
Lymphocytic interstitial pneumonitis, autoimmunity
13. Hepatic veno-occlusive disease with immunodeficiency (VODI) Mutations in SP110 AR Normal (decreased memory T cells) Normal (decreased memory B cells) Decreased IgG, IgA, IgM, absent germinal centers, absent tissue plasma cells Hepatic veno-occlusive disease; Pneumocystis jiroveci pneumonia; susceptibility to CMV, Candida; thrombocytopenia; hepatosplenomegaly 235550
14. IKAROS deficiencya Mutation in IKAROS AD de novo Normal, but impaired lymphocyte proliferation Absent Presumably decreased Anemia, neutropenia, thrombocytopenia Not assigned
15. FILS syndromea Mutation in POLE1; defective DNA replication AR Low naïve T cells; decreased T cell proliferation Low memory B cells Decreased IgM and IgG; lack of antibodies to polysaccharide antigens Mild facial dysmorphism (malar hypoplasia, high forehead), livedo, short stature; recurrent upper and lower respiratory tract infections, recurrent pulmonary infections, and recurrent meningitis 615139
16. Immunodeficiency with multiple intestinal atresias Mutation in TTC7A [tetratricopeptide repeat (TPR) domain 7A] protein of unknown function AR Variable, but sometimes absent Normal Decreased Multiple intestinal atresias, often with intrauterine polyhydramnios and early demise; some with SCID phenotype 243150

SCID, severe combined immune deficiencies; XL, X-linked inheritance; AR, autosomal recessive inheritance; AD, autosomal dominant inheritance; MSMD, Mendelian susceptibility of mycobacterial disease.

aTen or fewer unrelated cases reported in the literature.

T and B cell number and function in these disorders exhibit a wide range of abnormality; the most severely affected cases meet diagnostic criteria for SCID or leaky SCID and require immune system restoring therapy such as allogeneic hematopoietic cell transplantation. While not all DOCK8-deficient patients have elevated serum IgE, most have recurrent viral infections and malignancies as a result of combined immunodeficiency. AR-HIES due to Tyk2 deficiency is also listed in Table 6, because of its association with atypical mycobacterial disease resulting in MSMD. Riddle syndrome is caused by mutations in a gene involved in DNA double-strand break repair and is associated with hypogammaglobulinemia. Autosomal dominant and autosomal recessive forms of dyskeratosis congenita are included in this table. IKAROS-deficiency represents a single prematurely born infant who died at the age of 87 days and who had absent B and NK cells and non-functional T cells.

Table 3.

Predominantly antibody deficiencies.

Disease Genetic defect/presumed pathogenesis Inheritance Serum Ig Associated features OMIM number
1. Severe reduction in all serum immunoglobulin isotypes with profoundly decreased or absent B cells
(a) BTK deficiency Mutations in BTK, a cytoplasmic tyrosine kinase activated by crosslinking of the BCR XL All isotypes decreased in majority of patients; some patients have detectable immunoglobulins Severe bacterial infections; normal numbers of pro-B cells 300300
(b) μ Heavy chain deficiency Mutations in μ heavy chain; essential component of the pre-BCR AR All isotypes decreased Severe bacterial infections; normal numbers of pro-B cells 147020
(c) λ5 Deficiencya Mutations in l5; part of the surrogate light chain in the pre-BCR AR All isotypes decreased Severe bacterial infections; normal numbers of pro-B cells 146770
(d) Igα deficiencya Mutations in Iga (CD79a); part of the pre-BCR and BCR AR All isotypes decreased Severe bacterial infections; normal numbers of pro-B cells 112205
(e) Igβ deficiencya Mutations in Igb (CD79β); part of the pre-BCR and BCR AR All isotypes decreased Severe bacterial infections; normal numbers of pro-B cells 147245
(f) BLNK deficiencya Mutations in BLNK; a scaffold protein that binds to BTK AR All isotypes decreased Severe bacterial infections; normal numbers of pro-B cells 604615
(g) PI3 kinase deficiencya Mutations in PIK3R1; a kinase involved in signal transduction in multiple cell types AR All isotypes decreased Severe bacterial infections; decreased or absent pro-B cells 171833
(h) E47 transcription factor deficiencya Mutations in TCF3; a transcription factor required for control of B cell development AD All isotypes decreased Recurrent bacterial infections 147141
(i) Myelodysplasia with hypogammaglobulinemia May have monosomy 7, trisomy 8, or dyskeratosis congenita Variable One or more isotypes may be decreased Infections; decreased number of pro-B cells Not assigned
(j) Thymoma with immunodeficiency Unknown None One or more isotypes may be decreased Bacterial and opportunistic infections; autoimmunity; decreased number of pro-B cells Not assigned
2. Severe reduction in at least two serum immunoglobulin isotypes with normal or low number of B cells
(a) Common variable immunodeficiency disorders Unknown Variable Low IgG and IgA and/or IgM Clinical phenotypes vary: most have recurrent infections, some have polyclonal lymphoproliferation, autoimmune cytopenias, and/or granulomatous disease Not assigned
(b) ICOS deficiencya Mutations in ICOS; a co-stimulatory molecule expressed on T cells AR Low IgG and IgA and/or IgM Recurrent infections; autoimmunity, gastroenteritis, granuloma in some 604558
(c) CD19 deficiencya Mutations in CD19; transmembrane protein that amplifies signal through BCR AR Low IgG and IgA and/or IgM Recurrent infections; may have glomerulonephritis 107265
(d) CD81 deficiencya Mutations in CD81; transmembrane protein that amplifies signal through BCR AR Low IgG, low or normal IgA and IgM Recurrent infections; may have glomerulonephritis 186845
(e) CD20 deficiencya Mutations in CD20; a B cell surface receptor involved in B cell development and plasma cell differentiation AR Low IgG, normal or elevated IgM and IgA Recurrent infections 112210
(f) CD21 deficiencya Mutations in CD21; also known as complement receptor 2 and forms part of the CD19 complex AR Low IgG; impaired anti-pneumococcal response Recurrent infections 614699
(g) TACI deficiency Mutations in TNFRSF13B (TACI); a TNF receptor family member found on B cells and is a receptor for BAFF and APRIL AD or AR or complex Low IgG and IgA and/or IgM Variable clinical expression 604907
(h) LRBA deficiency Mutations in LRBA (lipopolysaccharide responsive beige-like anchor protein) AR Reduced I IgG and IgA in most Recurrent infections, inflammatory bowel disease, autoimmunity; EBV infections 606453
(i) BAFF receptor deficiencya Mutations in TNFRSF13C (BAFF-R); a TNF receptor family member found on B cells and is a receptor for BAFF AR Low IgG and IgM Variable clinical expression 606269
(j) TWEAKa Mutations in TWEAK AD Low IgM and IgA; lack of anti-pneumococcal antibody Pneumonia, bacterial infections, warts; thrombocytopenia. neutropenia 602695
(k) NFKB2 deficiencya Mutations in NFKB2; an essential component of the non-canonical NF-κB pathway AD Low IgG and IgA and IgM Recurrent infections 615577
(l) Warts, hypogammaglobulinemia, infections, myelokathexis (WHIM) syndrome Gain-of-function mutations of CXCR4, the receptor for CXCL12 AD Panhypogammaglobulinemia, decreased B cells Warts/human papilloma virus (HPV) infection Neutropenia Reduced B cell number Hypogammaglobulinemia 193670
3. Severe reduction in serum IgG and IgA with normal/elevated IgM and normal numbers of B cells
(a) CD40L deficiency Mutations in CD40LG (also called TNFSF5 or CD154) XL IgG and IgA decreased; IgM may be normal or increased; B cell numbers may be normal or increased Bacterial and opportunistic infections, neutropenia, autoimmune disease 300386
(b) CD40 deficiencya Mutations in CD40 (also called TNFRSF5) AR Low IgG and IgA; normal or raised IgM Bacterial and opportunistic infections, neutropenia, autoimmune disease 109535
(c) AID deficiency Mutations in AICDA gene AR IgG and IgA decreased; IgM increased Bacterial infections, enlarged lymph nodes, and germinal centers 605257
(d) UNG deficiency Mutations in UNG AR IgG and IgA decreased; IgM increased Enlarged lymph nodes and germinal centers 191525
4. Isotype or light chain deficiencies with generally normal numbers of B cells
(a) Ig heavy chain mutations and deletions Mutation or chromosomal deletion at 14q32 AR One or more IgG and/or IgA subclasses as well as IgE may be absent May be asymptomatic Not assigned
(b) κ Chain deficiencya Mutations in Kappa constant gene AR All immunoglobulins have lambda light chain Asymptomatic 147200
(c) Isolated IgG subclass deficiency Unknown Variable Reduction in one or more IgG subclass Usually asymptomatic; a minority may have poor antibody response to specific antigens and recurrent viral/bacterial infections Not assigned
(d) IgA with IgG subclass deficiency Unknown Variable Reduced IgA with decrease in one or more IgG subclass Recurrent bacterial infections Not assigned
(e) PRKC δ deficiencya Mutation in PRKCD; encoding a member of the protein kinase C family critical for regulation of cell survival, proliferation, and apoptosis AR Low IgG levels; IgA and IgM above the normal range Recurrent infections; EBV chronic infection Lymphoproliferation SLE-like autoimmunity (nephrotic and antiphospholipid syndromes) 615559
(f) Activated PI3K-δ Mutation in PIK3CD, PI3K-δ AD gain-of-function Reduced IgG2 and impaired antibody to pneumococci and hemophilus Respiratory infections, bronchiectasis; autoimmunity; chronic EBV, CMV infection 602839
(g) Selective IgA deficiency Unknown Variable IgA decreased/absent Usually asymptomatic; may have recurrent infections with poor antibody responses to carbohydrate antigens; may have allergies or autoimmune disease. A very few cases progress to CVID, others coexist with CVID in the family 137100
5. Specific antibody deficiency with normal Ig concen-trations and normal numbers of B cells Unknown Variable Normal Reduced ability to produce antibodies to specific antigens Not assigned
6. Transient hypogammaglobulinemia of infancy with normal numbers of B cells Unknown Variable IgG and IgA decreased Normal ability to produce antibodies to vaccine antigens, usually not associated with significant infections Not assigned

XL, X-linked inheritance; AR, autosomal recessive inheritance; AD, autosomal dominant inheritance; BTK, Bruton tyrosine kinase; BLNK, B cell linker protein; AID, activation-induced cytidine deaminase; UNG, uracil-DNA glycosylase; ICOS, inducible costimulator; Ig(κ), immunoglobulin or κ light chain type.

aTen or fewer unrelated cases reported in the literature.

Several autosomal recessive disorders that might previously have been called CVID have been added to Table 3. CD81 is normally co-expressed with CD19 on the surface of B cells. As for CD19 mutations, mutations in CD81 result in normal numbers of peripheral blood B cells, low serum IgG, and an increased incidence of glomerulonephritis. Single patient with a homozygous mutation in CD20 and CD21 has been reported.

Common variable immunodeficiency disorders (CVID) include several clinical and laboratory phenotypes that may be caused by distinct genetic and/or environmental factors. Some patients with CVID and no known genetic defect have markedly reduced numbers of B cells as well as hypogammaglobulinemia. Alterations in TNFRSF13B (TACI) and TNFRSF13C (BAFF-R) sequences may represent disease-modifying mutations rather than disease causing mutations. CD40L and CD40 deficiency are included in Table 1 as well as this table. A small minority of patients with XLP (Table 4), WHIM syndrome (Table 6), ICF (Table 2), VOD1 (Table 2), thymoma with immunodeficiency (Good syndrome), or myelodysplasia are first seen by an immunologist because of recurrent infections, hypogammaglobulinemia, and normal or reduced numbers of B cells. Patients with GATA2 mutations (Table 5) may have markedly reduced numbers of B cells, as well as decreased monocytes and NK cells, and a predisposition to myelodysplasia but they do not usually have an antibody deficiency.

Table 8.

Complement deficiencies.

Disease Genetic defect; presumed pathogenesis Inheritance Functional defect Associated features OMIM number
1. C1q deficiency Mutation in C1QA, C1QB, C1QC: classical complement pathway components AR Absent CH50 hemolytic activity, defective activation of the classical pathway SLE, infections with encapsulated organisms 120550; 601269; 120575
Diminished clearance of apoptotic cells
2. C1r deficiency Mutation in C1R: classical complement pathway component AR Absent CH50 hemolytic activity, defective activation of the classical pathway SLE, infections with encapsulated organisms 216950
3. C1s deficiency Mutation in C1S: classical complement pathway component AR Absent CH50 hemolytic activity, defective activation of the classical pathway SLE, infections with encapsulated organisms 120580
4. C4 deficiency Mutation in C4A, C4B: classical complement pathway components AR Absent CH50 hemolytic activity, defective activation of the classical pathway, defective humoral immune response to carbohydrate antigens in some patients SLE, infections with encapsulated organisms 120810; 120820
5. C2 deficiency Mutation in C2: classical complement pathway component AR Absent CH50 hemolytic activity, defective activation of the classical pathway SLE, infections with encapsulated organisms, atherosclerosis 217000
6. C3 deficiency Mutation in C3: central complement component AR, gain-of-function AD Absent CH50 and AH50 hemolytic activity defective opsonization Infections; glomerulonephritis 120700
Defective humoral immune response Atypical hemolytic–uremic syndrome with gain-of-function mutations
7. C5 deficiency Mutation in C5: terminal complement component AR Absent CH50 and AH50 hemolytic activity; defective bactericidal activity Neisserial infections 120900
8. C6 deficiency Mutation in C6: terminal complement component AR Absent CH50 and AH50 hemolytic activity; defective bactericidal activity Neisserial infections 217050
9. C7 deficiency Mutation in C7: terminal complement component AR Absent CH50 and AH50 hemolytic activity; defective bactericidal activity Neisserial infections 217070
10. C8 α–γ deficiency Mutation in C8A, C8G: terminal complement components AR Absent CH50 and AH50 hemolytic activity; defective bactericidal activity Neisserial infections 120950
11. C8b deficiency Mutation in C8B: Terminal complement component AR Absent CH50 and AH50 hemolytic activity; defective bactericidal activity Neisserial infections 120960
12. C9 deficiency Mutation in C9: Terminal complement component AR Reduced CH50 and AP50 hemolytic activity; deficient bactericidal activity Mild susceptibility to Neisserial infections 613825
13. C1 inhibitor deficiency Mutation in SERPING1: regulation of kinins and complement activation AD Spontaneous activation of the complement pathway with consumption of C4/C2 Hereditary angioedema 138470
Spontaneous activation of the contact system with generation of bradykinin from high molecular weight kininogen
14. Factor Ba Mutation in CFB: activation of the alternative pathway AD Gain-of-function mutation with increased spontaneous AH50 aHUS 138470
15. Factor D deficiency Mutation in CFD: regulation of the alternative complement pathway AR Absent AH50 hemolytic activity Neisserial infections 134350
16. Properdin deficiency Mutation in CFP: regulation of the alternative complement pathway XL Absent AH50 hemolytic activity Neisserial infections 312060
17. Factor I deficiency Mutation in CFI: regulation of the alternative complement pathway AR Spontaneous activation of the alternative complement pathway with consumption of C3 Infections, Neisserial infections, aHUS, preeclampsia, membranoproliferative glomerulonephritis (MPGN) 610984
18. Factor H deficiency Mutation in CFH: regulation of the alternative complement pathway AR Spontaneous activation of the alternative complement pathway with consumption of C3 Infections, Neisserial infections, aHUS, preeclampsia, membranoproliferative glomerulonephritis (MPGN) 609814
19. Factor H-related protein deficiencies Mutation in CFHR1-5: bind C3b AR Normal CH50, AH50, autoantibodies to Factor H aHUS 235400
20. Thrombomodulina Mutation in THBD: regulates complement and coagulant activation AD Normal CH50, AH50 aHUS 188040
21. MASP1 deficiency Mutation in MASP1: cleaves C2 and activates MASP2 AR Deficient activation of the lectin activation pathway, cell migration Infections, 3MC syndrome 600521
22. MASP2 deficiencya MASP2: cleavage of C2 and C4 AR Deficient activation of the lectin activation pathway Pyogenic infections; inflammatory lung disease, autoimmunity 605102
23. 3MC syndrome COLEC11 deficiencya Mutation in COLEC11: binds MASP1, MASP3 AR Loss of neural crest cell migration signals A developmental syndrome of facial dysmorphism, cleft lip and/or palate, craniosynostosis, learning disability, and genital, limb, and vesicorenal anomalies (3MC syndrome) 612502
24. Complement receptor 2 (CR2) deficiencya Mutation in CD21 AR See CD21 deficiency in Table 3 120650
25. Complement receptor 3 (CR3) deficiency Mutation in ITGB2 AR See LAD1 in Table 5 116920
Membrane cofactor protein (CD46) deficiency Mutation in CD46: dissociates C3b and C4b AD Inhibitor of complement alternate pathway, decreased C3b binding aHUS, infections, preeclampsia 120920
Membrane Attack Complex inhibitor (CD59) deficiencya Mutation in CD59: regulates the membrane attack complex formation AR Erythrocytes highly susceptible to complement-mediated lysis Hemolytic anemia, polyneuropathy 107271
Ficolin 3 deficiencya Mutation in FCN3: activates the classical complement pathway AR Absence of complement activation by the Ficolin 3 pathway Respiratory infections, abscesses 604973

XL, X-linked inheritance; AR, autosomal recessive inheritance; AD, autosomal dominant inheritance; MAC, membrane attack complex; SLE, systemic lupus erythematosus; MBP, mannose-binding protein; MASP2, MBP-associated serine protease 2.

aTen or fewer unrelated cases reported in the literature.

New entities added to Table 8 demonstrate the important role of complement regulators in a group of well-described inflammatory disorders. In particular, we have added mutations in membrane bound as well as surface attached soluble complement regulatory proteins recognized in hemolytic–uremic syndrome, age-related macular degeneration, and preeclampsia. The connecting theme of these otherwise unrelated clinical events is excessive activation or insufficient regulation of C3; these events lead to recruitment of leukocytes and permit secretion of inflammatory and anti-angiogenic mediators that disrupt the vascular bed of the target organ. Alterations in the genes for Factor B (CFB), Factor I (CFI), Factor H (CFH), and CD46 act as susceptibility genes rather than disease causing mutations. Population studies reveal no detectable increase in infections in MBP (also known at mannose-binding lectin – MBL) deficient adults. The 3MC syndrome, a developmental syndrome, has been variously called Carnevale, Mingarelli, Malpuech, and Michels syndrome.

Table 5.

Congenital defects of phagocyte number, function, or both.

Disease Genetic defect/presumed pathogenesis Inheritance Affected cells Affected function Associated features OMIM number
1. Defects of neutrophil function
(a) Severe congenital neutropenia 1 (ELANE deficiency) Mutation in ELANE: misfolded protein response, increased apoptosis AD N Myeloid differentiation Susceptibility to MDS/leukemia 202700
(b) SCN2a (GFI 1 deficiency) Mutation in GFI1: loss of repression of ELANE AD N Myeloid differentiation B/T lymphopenia 613107
(c) SCN3 (Kostmann disease) Mutation in HAX1: control of apoptosis AR N Myeloid differentiation Cognitive and neurological defects in patients with defects in both HAX1 isoforms, susceptibility to MDS/leukemia 610738
(d) SCN4 (G6PC3 deficiency) Mutation in G6PC3: abolished enzymatic activity of glucose-6-phosphatase, aberrant glycosylation, and enhanced apoptosis of N and F AR N + F Myeloid differentiation, chemotaxis, O2production Structural heart defects, urogenital abnormalities, inner ear deafness, and venous angiectasias of trunks and limbs 612541
(e) SCN5 Mutation in VPS45 controls vesicular trafficking AR N + F Myeloid differentiation, migration Extramedullary hematopoiesis, bone marrow fibrosis, nephromegaly 615285
(f) Glycogen storage disease type 1b Mutation in G6PT1: glucose-6-phosphate transporter 1 AR N + M Myeloid differentiation, chemotaxis, O2production Fasting hypoglycemia, lactic acidosis, hyperlipidemia, hepatomegaly 232220
(g) Cyclic neutropenia Mutation in ELANE: misfolded protein response AD N Differentiation Oscillations of other leukocytes and platelets 162800
(h) X-linked neutropenia/amyelodysplasia Mutation in WAS: regulator of actin cytoskeleton (loss of auto-inhibition) XL, gain-of-function N + M Mitosis Monocytopenia 300299
(i) P14/LAMTOR2 deficiencya Mutation in ROBLD3/LAMTOR2: endosomal adaptor protein 14 AR N + L Mel Endosome biogenesis Neutropenia 610389
Hypogammaglobulinemia
↓CD8 cytotoxicity
Partial albinism
Growth failure
(j) Barth syndrome Mutation in tafazzin (TAZ) gene: abnormal lipid structure of mitochondrial membrane, defective carnitine metabolism XL N Myeloid differentiation Cardiomyopathy, myopathy, growth retardation 302060
(k) Cohen syndrome Mutation in COH1 gene: Pg unknown AR N Myeloid differentiation Retinopathy, developmental delay, facial dysmorphisms 216550
(l) Clericuzio syndrome poikiloderma with neutropenia Mutation in C16ORF57, affects genomic integrity AR N Myeloid differentiation Poikiloderma, neutropenia, MDS 613276
2. Defects of motility
(a) Leukocyte adhesion deficiency type 1 (LAD1) Mutation in ITGB2: adhesion protein (CD18) AR N + M + L + NK Adherence, chemotaxis, endocytosis, T/NK cytotoxicity Delayed cord separation, skin ulcers Periodontitis Leukocytosis 116920
(b) Leukocyte adhesion deficiency type 2 (LAD2)a Mutation in FUCT1: GDP-fucose transporter AR N + M Rolling, chemotaxis Mild LAD type 1 features plus hh-blood group plus mental and growth retardation 266265
(c) Leukocyte adhesion deficiency type 3 (LAD3) Mutation in KINDLIN3: Rap1-activation of β1–3 integrins AR N + M + L + NK Adherence, chemotaxis LAD type 1 plus bleeding tendency 612840
(d) Rac 2 deficiencya Mutation in RAC2: regulation of actin cytoskeleton AD N Adherence, chemotaxis, O2production Poor wound healing, leukocytosis 602049
(e) β-Actin deficiencya Mutation in ACTB: cytoplasmic actin AD N + M Motility Mental retardation, short stature 102630
(f) Localized juvenile periodontitis Mutation in FPR1: chemokine receptor AR N Formylpeptide induced chemotaxis Periodontitis only 136537
(g) Papillon–Lefèvre syndrome Mutation in CTSC: cathepsin C activation of serine proteases AR N + M Chemotaxis Periodontitis, palmoplantar hyperkeratosis in some patients 245000
(h) Specific granule deficiencya Mutation in C/EBPE: myeloid transcription factor AR N Chemotaxis Neutrophils with bilobed nuclei; absent secondary granules and defensins 245480
(i) Shwachman–Diamond syndrome Mutation in SBDS: defective ribosome synthesis AR N Chemotaxis Pancytopenia, exocrine pancreatic insufficiency, chondrodysplasia 260400
3. Defects of respiratory burst
(a) X-linked chronic granulomatous disease (CGD) Mutation in CYBB: electron transport protein (gp91phox) XL N + M Killing (faulty O2production) Recurrent bacterial infection, susceptibility to fungal infection, inflammatory gut manifestations McLeod phenotype in patients with deletions extending into the contiguous Kell locus 306400
(b) Autosomal recessive CGD – p22 phox deficiency Mutation in CYBA: electron transport protein (p22phox) AR N + M Killing (faulty O2production) Recurrent bacterial infection, susceptibility to fungal infection, and inflammatory gut manifestations 233690
(c) Autosomal recessive CGD – p47 phox deficiency Mutation in NCF1: adapter protein (p47phox) AR N + M Killing (faulty O2production) Recurrent bacterial infection, susceptibility to fungal infection, and inflammatory gut manifestations 233700
(d) Autosomal recessive CGD – p67 phox deficiency Mutation in NCF2: activating protein (p67phox) AR N + M Killing (faulty O2production) Recurrent bacterial infection, susceptibility to fungal infection, inflammatory gut manifestations 233710
(e) Autosomal recessive CGD – p40 phox deficiencya Mutation in NCF4: activating protein (p40phox) AR N + M Killing (faulty O2production) Inflammatory gut manifestations only 601488
4. Mendelian susceptibility to mycobacterial disease (MSMD)
(a) IL-12 and IL-23 receptor β1 chain deficiency Mutation in IL-12RB1: IL-12 and IL-23 receptor β1 chain AR L + NK IFN-γ secretion Susceptibility to Mycobacteria and Salmonella 209950
(b) IL-12p40 deficiency Mutation in IL-12B: subunit p40 of IL-12/IL-23 AR M IFN-γ secretion Susceptibility to Mycobacteria and Salmonella 161561
(c) IFN-γ receptor 1 deficiency Mutation in IFNGR1: IFN-γR ligand binding chain AR, AD M + L IFN-γ binding and signaling Susceptibility to Mycobacteria and Salmonella 107470
(d) IFN-γ receptor 2 deficiency Mutation in IFNGR2: IFN-γR accessory chain AR M + L IFN-γ signaling Susceptibility to Mycobacteria and Salmonella 147569
(e) STAT1 deficiency (AD form)a Mutation in STAT1 (loss of function) AD M + L IFN-γ signaling Susceptibility to Mycobacteria 600555
(f) Macrophage gp91 phox deficiencya Mutation in CYBB: electron transport protein (gp 91 phox) XL Mf only Killing (faulty O2production) Isolated susceptibility to Mycobacteria 306400
(g) IRF8-deficiency (AD form)a Mutation in IRF8: IL-12 production by CD1c+ MDC AD CD1c+ MDC Differentiation of CD1c+ MDC subgroup Susceptibility to Mycobacteria 601565
(h) ISG15 Mutation in ISG15; an interferon (IFN) α/β-inducible, ubiquitin-like intracellular protein AR M + N + L IFN-γ secretion Susceptibility to Mycobacteria 14751
5. Other defects
(a) IRF 8-deficiency (AR form)a Mutation in IRF8: IL-12 production AR Monocytes peripheral DC Cytopenias Susceptibility to Mycobacteria, Candida, myeloproliferation 614893
(b) GATA2 deficiency (Mono MAC syndrome) Mutation in GATA2: loss of stem cells AD Monocytes peripheral DC + NK + B Multilineage cytopenias Susceptibility to Mycobacteria, papilloma viruses, histoplasmosis, alveolar proteinosis, MDS/AML/CMML 137295
(c) Pulmonary alveolar proteinosisa Mutation in CSF2RA Biallelic mutations in pseudo-autosomal gene Alveolar macro-phages GM-CSF signaling Alveolar proteinosis 306250

XL, X-linked inheritance; AR, autosomal recessive inheritance; AD, autosomal dominant inheritance; ACTB, actin beta; B, B lymphocytes; CEBPE, CCAAT/enhancer-binding protein epsilon; CMML, chronic myelomonocytic leukemia; CTSC, cathepsin C; CYBA, cytochrome b alpha subunit; CYBB, cytochrome b beta subunit; DC, dendritic cells; ELANE, elastase neutrophil-expressed; GATA2, GATA binding protein 2; IFN, interferon; IFNGR1, interferon-gamma receptor subunit 1; IFNGR2, interferon-gamma receptor subunit 2; IL-12B, interleukin-12 beta subunit; IL-12RB1, interleukin-12 receptor beta 1; IFR8, interferon regulatory factor 8; F, fibroblasts; FPR1, formylpeptide receptor 1; FUCT1, fucose transporter 1; GFI1, growth factor independent 1; HAX1, HLCS1-associated protein X1; ITGB2, integrin beta-2; L, lymphocytes; M, monocytes–macrophages; MDC, myeloid dendritic cells; MDS, myelodysplasia; Mel, melanocytes; Mϕ, macrophages; MSMD, Mendelian susceptibility to mycobacterial disease; N, neutrophils; NCF1, neutrophil cytosolic factor 1; NCF2, neutrophil cytosolic factor 2; NCF4, neutrophil cytosolic factor 4; NK, natural killer cells; ROBLD3: roadblock domain containing 3; SBDS, Shwachman–Bodian–Diamond syndrome; STAT, signal transducer and activator of transcription.

aTen or fewer unrelated cases reported in the literature.

Table 5 includes seven newly described genetic defects of phagocyte number and/or function including Barth syndrome, Cohen syndrome, and poikiloderma with neutropenia. In these three clinically well-known diseases, the genetic defects have been elucidated, although their molecular pathogenesis remains ill-defined. A new cause of autosomal recessive chronic granulomatous disease, namely a deficiency of the cytosolic activating protein p40 phox, has now been found in two CGD patients and is included under defects of respiratory burst. Under the heading of Mendelian susceptibility of mycobacterial disease (MSMD), two new entities were added: (a) a subgroup of X-linked gp91 phox deficiency with isolated susceptibility to mycobacteria and a defect of the respiratory burst in macrophages only; (b) an autosomal dominant form of IRF8-deficiency, resulting from a lack of CD1c+ myeloid dendritic cells that would normally secrete IL-12. The clinical phenotype of MSMD may vary, depending on the nature of the genetic defect. Finally, GATA2 deficiency was recently identified as the cause of the Mono MAC syndrome, with multilineage cytopenias (of monocytes, peripheral dendritic cells, NK- and B-lymphocytes) resulting in opportunistic infections (including mycobacteria), alveolar proteinosis, and malignancy.

Table 6.

Defects in innate immunity.

Disease Genetic defect/presumed pathogenesis Inheritance Affected cell Functional defect Associated features OMIM number
1. Anhidrotic ectodermal dysplasia with immunodeficiency (EDA-ID)
(a) EDA-ID, X-linked (NEMO deficiency) Mutations of NEMO (IKBKG), a modulator of NF-κB activation XL Lymphocytes + monocytes NF-κB signaling pathway Various infections (bacteria, Mycobacteria, viruses, and fungi) 300248
Colitis
EDA (not in all patients)
Hypogammaglobulinemia to specific antibody polysaccharides deficiency
(b) EDA-ID, autosomal-dominanta Gain-of-function mutations of IKBA, resulting in impaired activation of NF-κB AD Lymphocytes + monocytes NF-κB signaling pathway Various infections (bacteria, viruses, and fungi) 612132
EDA
T cell defect
2. TIR signaling pathway deficiency
(a) IRAK-4 deficiency Mutations of IRAK-4, a component of TLR- and IL-1R-signaling pathway AR Lymphocytes + granulocytes + monocytes TIR–IRAK signaling pathway Bacterial infections (pyogenes) 607676
(b) MyD88 deficiency Mutations of MYD88, a component of the TLR and IL-1R signaling pathway AR Lymphocytes + granulocytes + monocytes TIR–MyD88 signaling pathway Bacterial infections (pyogenes) 612260
3. HOIL1 deficiencya Mutation of HOIL1, a component of LUBAC AR Lymphocytes + granulocytes + monocytes NF-κB signaling pathway Bacterial infections (pyogenes) Not assigned
Autoinflammation
Amylopectinosis
4. WHIM (Warts, hypogammaglobulinemia, infections, myelokathexis) syndrome Gain-of-function mutations of CXCR4, the receptor for CXCL12 AD Granulocytes + lymphocytes Increased response of the CXCR4 chemokine receptor to its ligand CXCL12 (SDF-1) Warts/human papilloma virus (HPV) infection 193670
Neutropenia
Reduced B cell number
Hypogammaglobulinemia
5. Epidermodysplasia verruciformis
EVER1 deficiency Mutations of EVER1 AR Keratinocytes and leukocytes EVER proteins may be involved in the regulation of cellular zinc homeostasis in lymphocytes HPV (group B1) infections and cancer of the skin (typical EV) 226400
EVER2 deficiency Mutations of EVER2 AR Keratinocytes and leukocytes EVER proteins may be involved in the regulation of cellular zinc homeostasis in lymphocytes HPV (group B1) infections and cancer of the skin (typical EV) 226400
6. Predisposition to severe viral infection
(a) STAT2 deficiencya Mutations of STAT2 AR T and NK cells STAT2-dependent Severe viral infections (disseminated vaccine-strain measles) Not assigned
IFN-α and -β response
(b) MCM4 deficiencya Mutations in MCM4 AR NK cells DNA repair disorder Viral infections (EBV, HSV, VZV) 609981
Adrenal failure
Short stature
7. Herpes simplex encephalitis (HSE)
(a) TLR3 deficiencya (b) Mutations of TLR3 AD Central nervous system (CNS) resident cells and fibroblasts TLR3-dependent Herpes simplex virus 1 encephalitis (incomplete clinical penetrance for all etiologies listed here) 613002
AR IFN-α, -β, and -λ induction
(b) UNC93B1 deficiencya (a) Mutations of UNC93B1 AR CNS resident cells and fibroblasts UNC-93B-dependent Herpes simplex virus 1 encephalitis 610551
IFN-α, -β, and -λ induction
(c) TRAF3 deficiencya (c) Mutations of TRAF3 AD CNS resident cells and fibroblasts TRAF3-dependent Herpes simplex virus 1 encephalitis 614849
IFN-α, -β, and -λ induction
(d) TRIF deficiencya (c) Mutations of TRIF AD CNS resident cells and fibroblasts TRIF-dependent Herpes simplex virus 1 encephalitis 614850
AR IFN-α, -β, and -λ induction
(e) TBK1 deficiencya (c) Mutations of TBK1 AD CNS resident cells and fibroblasts TBK1-dependent Herpes simplex virus 1 encephalitis Not assigned
IFN-α, -β, and -λ induction
8. Predisposition to invasive fungal diseasesa
CARD9 deficiency Mutations of CARD9 AR Mononuclear phagocytes CARD9 signaling pathway Invasive candidiasis infection Deep dermatophytoses 212050
9. Chronic mucocutaneous candidiasis (CMC)
(a) IL-17RA deficiencya (a) Mutations in IL-17RA AR Epithelial cells, fibroblasts, mononuclear phagocytes IL-17RA signaling pathway CMC Folliculitis 605461
(b) IL-17F deficiencya (b) Mutations in IL-17F AD T cells IL-17F-containing dimers CMC Folliculitis 606496
(c) STAT1 gain-of-function (c) Gain-of-function mutations in STAT1 AD T cells Gain-of-function STAT1 mutations that impair the development of IL-17-producing T cells CMC 614162
Various fungal, bacterial, and viral (HSV) infections
Autoimmunity (thyroiditis, diabetes, cytopenia)
Enteropathy
(d) ACT1 deficiencya (c) Mutations in ACT1 AR T cells, fibroblasts Fibroblasts fail to respond to IL-17A and IL-17F, and their T cells to IL-17E CMC 615527
Blepharitis, folliculitis, and macroglossia
10. Trypanosomiasisa Mutations in APOL-I AD APOL-I Trypanosomiasis 603743
11. Isolated congenital asplenia (ICA) Mutations in RPSA AD Spleen RPSA encodes ribosomal protein SA, a component of the small subunit of the ribosome Bacteremia (encapsulated bacteria) No spleen 271400

XL, X-linked inheritance; AR, autosomal recessive inheritance; AD, autosomal dominant inheritance; NF-κB, nuclear factor kappa B; TIR, Toll and interleukin 1 receptor; IFN, interferon; HVP, human papilloma virus; TLR, Toll-like receptor; IL, interleukin.

aTen or fewer unrelated cases reported in the literature.

Eight new disorders have been added to Table 6. Three new entries have been added in the table. One is a new PID with the association of recurrent bacterial infections, autoinflammation, and amylopectinosis caused by AR HOIL1 mutations found in two kindreds. The second is severe viral infection, for which three genetic etiologies have been discovered. AR-STAT2 deficiency and AR-CD16 deficiency have been found in one kindred each. AR MCM4 deficiency has been found in several Irish kindreds. The third is isolated congenital asplenia identified in 18 patients from 8 kindreds.

XR-EDA-ID is highly heterogeneous clinically, both in terms of developmental features (some patients display osteopetrosis and lymphedema, in addition to EDA, while others do not display any developmental features) and infectious diseases (some display multiple infections, viral, fungal, and bacterial, while others display a single type of infection). The various OMIM entries correspond to these distinct clinical diseases.

Table 7.

Autoinflammatory disorders.

Disease Genetic defect/presumed pathogenesis Inheritance Affected cells Functional defects Associated features OMIM number
1. Defects effecting the inflammasome
(a) Familial Mediterranean fever Mutations of MEFV (lead to gain of pyrin function, resulting in inappropriate IL-1β release) AR Mature granulocytes, cytokine-activated monocytes Decreased production of pyrin permits ASC-induced IL-1 processing and inflammation following subclinical serosal injury; macrophage apoptosis decreased Recurrent fever, serositis, and inflammation responsive to colchicine. Predisposes to vasculitis and inflammatory bowel disease 249100
(b) Mevalonate kinase deficiency (hyper IgD syndrome) Mutations of MVK (lead to a block in the mevalonate pathway). Interleukin-1beta mediates the inflammatory phenotype AR Affecting cholesterol synthesis; pathogenesis of disease is unclear Periodic fever and leukocytosis with high IgD levels 260920
(c) Muckle–Wells syndrome Mutations of CIAS1 (also called PYPAF1 or NALP3) lead to constitutive activation of the NLRP3 inflammasome AD PMNs monocytes Defect in cryopyrin, involved in leukocyte apoptosis and NF-κB signaling and IL-1 processing Urticaria, SNHL, amyloidosis 191900
(d) Familial cold autoinflammatory syndrome Mutations of CIAS1 (see above) Mutations of NLRP12 AD PMNs, monocytes Same as above Non-pruritic urticaria, arthritis, chills, fever, and leukocytosis after cold exposure 120100
5. Neonatal onset multisystem inflammatory disease (NOMID) or chronic infantile neurologic cutaneous and articular syndrome (CINCA) Mutations of CIAS1 (see above) AD PMNs, chondrocytes Same as above Neonatal onset rash, chronic meningitis, and arthropathy with fever and inflammation 607115
2. Non inflammasome-related conditions
(a) TNF receptor-associated periodic syndrome (TRAPS) Mutations of TNFRSF1 (resulting in increased TNF inflammatory signaling) AD PMNs, monocytes Mutations of 55-kDa TNF receptor leading to intracellular receptor retention or diminished soluble cytokine receptor available to bind TNF Recurrent fever, serositis, rash, and ocular or joint inflammation 142680
(b) Early-onset inflammatory bowel disease Mutations in IL-10 (results in increase many proinflammatory cytokines) AR Monocyte/macrophage, activated T cells IL-10 deficiency leads to increase of TNFγ and other proinflammatory cytokines Early-onset enterocolitis enteric fistulas, perianal abscesses, chronic folliculitis 124092
(b) Early-onset inflammatory bowel disease Mutations in IL-10RA (see above) AR Monocyte/macrophage, activated T cells Mutation in IL-10 receptor alpha leads to increase of TNFγ and other proinflammatory cytokines Early-onset enterocolitis enteric fistulas, perianal abscesses, chronic folliculitis 146933
(b) Early-onset inflammatory bowel disease Mutations in IL-10RB (see above) AR Monocyte/macrophage, activated T cells Mutation in IL-10 receptor beta leads to increase of TNFγ and other proinflammatory cytokines Early-onset enterocolitis enteric fistulas, perianal abscesses, chronic folliculitis 123889
(c) Pyogenic sterile arthritis, pyoderma gangrenosum, acne (PAPA) syndrome Mutations of PSTPIP1 (also called C2BP1) (affects both pyrin and protein tyrosine phosphatase to regulate innate and adaptive immune responses) AD Hematopoietic tissues, upregulated in activated T cells Disordered actin reorganization leading to compromised physiologic signaling during inflammatory response Destructive arthritis, inflammatory skin rash, myositis 604416
(d) Blau syndrome Mutations of NOD2 (also called CARD15) (involved in various inflammatory processes) AD Monocytes Mutations in nucleotide binding site of CARD15, possibly disrupting interactions with lipopolysaccharides and NF-κB signaling Uveitis, granulomatous synovitis, camptodactyly, rash, and cranial neuropathies, 30% develop Crohn’s disease 186580
10. Chronic recurrent multifocal osteomyelitis and congenital dyserythropoietic anemia (Majeed syndrome)a Mutations of LPIN2 (increased expression of the proinflammatory genes) AR Neutrophils, bone marrow cells Undefined Chronic recurrent multifocal osteomyelitis, transfusion-dependent anemia, cutaneous inflammatory disorders 609628
11. DIRA (deficiency of the interleukin 1 receptor antagonist)a Mutations of IL-1RN (see functional defect) AR PMNs, monocytes Mutations in the IL-1 receptor antagonist allow unopposed action of Interleukin 1 Neonatal onset of sterile multifocal osteomyelitis, periostitis, and pustulosis 612852
12. DITRA – deficiency of IL-36 receptor antagonist Mutation in IL-36RN (see functional defect) AR Keratinocyte leukocytes Mutations in IL-36RN leads to increase IL-8 production Pustular psoriasis 614204
13. SLC29A3 mutation Mutation in SLC29A3 (?) AR Leukocyte, bone cells Macrophage activation? Hyperpigmentation hypertrichosis 602782
14. CAMPS (CARD14 mediated psoriasis) Mutation in CARD14 (see functional defect) AD Mainly in keratinocyte Mutations in CARD14 activate the NF-κB pathway and production of IL-8 Psoriasis 173200
15. Cherubism Mutation in SH3BP2 (see functional defect) AD Stroma cells, bone cells Hyperactivated macrophage and increased NF-κB Bone degeneration in jaws 11840
16. CANDLE (chronic atypical neutrophilic dermatitis with lipodystrophy) Mutation in PSMB8 (see functional defect) AD Keratinocyte, B cell adipose cells Mutations cause increase IL-6 production Dystrophy, panniculitis 256040
17. HOIL1 deficiency Mutation in HOIL1 (see functional defect) AR PMNs, fibroblast Mutation in HOIL1 leads to IL-1β dysfunction Immunodeficiency autoinflammation amylopectinosis 610924
18. PLAID (PLCγ2 associated antibody deficiency and immune dysregulation) Mutation in PLCG2 (see functional defect) AD B cells, NK, mast cells Mutations cause activation of IL-1 pathways Cold urticaria hypogammaglobulinemia 614878

AR, autosomal recessive inheritance; AD, autosomal dominant inheritance; PMN, polymorphonuclear cells; ASC, apoptosis-associated speck-like protein with a caspase recruitment domain; CARD, caspase recruitment domain; CD2BP1, CD2 binding protein 1; PSTPIP1, proline/serine/threonine phosphatase-interacting protein 1; SNHL, sensorineural hearing loss; CIAS1, cold-induced autoinflammatory syndrome 1.

aTen or fewer unrelated cases reported in the literature.

Autoinflammatory diseases are clinical disorders marked by abnormally increased inflammation, mediated predominantly by the cells and molecules of the innate immune system, with a significant host predisposition. While the genetic defect of one of the most common autoinflammatory conditions, PFAPA, is not known, recent studies suggest that it is associated with activation of IL-1 pathway and response to IL-1beta antagonists.

Muckle–Wells syndrome, familial cold autoinflammatory syndrome and neonatal onset multisystem inflammatory disease (NOMID), which is also called chronic infantile neurologic cutaneous and articular syndrome (CINCA) are caused by similar mutations in CIAS1 mutations. The disease phenotype in any individual appears to depend on modifying effects of other genes and environmental factors.

In this updated version, we have added a new category in Table 9 in which “Phenocopies of PID” are listed. This has resulted from our understanding and study of conditions that present as inherited immunodeficiencies, but which are not due to germline mutations and instead arise from acquired mechanisms. Examples include somatic mutations in specific immune cell populations that give rise to the phenotype of autoimmune lymphoproliferative syndrome (ALPS), and also autoantibodies against specific cytokines or immunological factors, with depletion of these factors leading to immunodeficiency. It is likely that increasing numbers of PID phenocopies will be identified in the future, and this may be the start of a much longer table.

Table 9.

Phenocopies of PID.

Disease Genetic defect/presumed pathogenesis Circulating T cells Circulating B cells Serum Ig Associated features/similar PID
Associated with somatic mutations
(a) Autoimmune lymphoproliferative syndrome (ALPS–SFAS) Somatic mutation in TNFRSF6 Increased CD4CD8double negative (DN) T alpha/beta cells Normal, but increased number of CD5+ B cells Normal or increased Splenomegaly, lymphadenopathy, autoimmune cytopenias
Defective lymphocyte apoptosis/ALPS–FAS (=ALPS type Im)
(b) RAS-associated autoimmune leukoproliferative disease (RALD) Somatic mutation in KRAS (gain-of-function) Normal B cell lymphocytosis Normal or increased Splenomegaly, lymphadenopathy, autoimmune cytopenias, granulocytosis, monocytosis/ALPS-like
(c) RAS-associated autoimmune leukoproliferative disease (RALD) Somatic mutation in NRAS (gain-of-function) Increased CD4CD8double negative (DN) T alpha/beta cells Lymphocytosis Splenomegaly, lymphadenopathy, autoantibodies/ALPS-like
Associated with autoantibodies
(a) Chronic mucocutaneous candidiasis (isolated or with APECED syndrome) Germline mutation in AIREAutoAb to IL-17 and/or IL-22 Normal Normal Normal Endocrinopathy, chronic mucocutaneous candidiasis/CMC
(b) Adult-onset immunodeficiency AutoAb to IFN gamma Decreased naive T cells Normal Normal Mycobacterial, fungal, Salmonella VZV infections/MSMD, or CID
(c) Recurrent skin infection AutoAb to IL-6 Normal Normal Normal Staphylococcal infections/STAT3 deficiency
(d) Pulmonary alveolar proteinosis AutoAb to GM-CSF Normal Normal Normal Pulmonary alveolar proteinosis, cryptococcal meningitis/CSF2RA deficiency
(e) Acquired angioedema AutoAb to CI inhibitor Normal Normal Normal Angioedema/C1 INH deficiency (hereditary angioedema)

As with all complex diseases, any classification cannot be strictly adhered to. Certain conditions fall into more than one category and so appear in more than one table. For example, CD40L ligand deficiency is reported in both Tables 1 and 3 as it was initially identified as a defect of B cell isotype switching but is now known to be a defect of co-stimulatory T cell help and function. Similarly, XLP1 due to defects in SH2D1A is listed in Table 1 – combined immunodeficiencies, due to defects of T cell cytotoxicity, T cell help, and B cell maturation, but also in Table 4 – diseases of immune dysregulation, due to the susceptibility to hemophagocytosis. There is a growing appreciation that there can be wide phenotypic viability within a specific genotype that is a product of varied specific mutations between different patients as well as other host and/or environmental factors. The complexities of these conditions in terms of clinical and immunological presentation and heterogeneity cannot be easily captured in the limited space of a table format. For this reason, the furthest left column contains the Online Mendelian Inheritance in Man (OMIM) reference for each condition to allow access to greater detail and updated information.

Table 4.

Diseases of immune dysregulation.

Disease Genetic defect/presumed pathogenesis Inheritance Circulating T cells Circulating B cells Functional defect Associated features OMIM number
1. Familial hemophagocytic lymphohistiocytosis (FHL) syndromes
 1.1 FHL syndromes without hypopigmentation
(a) Perforin deficiency (FHL2) Mutations in PRF1; perforin is a major cytolytic protein AR Increased activated T cells Normal Decreased to absent NK and CTL activities (cytotoxicity) Fever, hepatosplenomegaly (HSMG), hemophagocytic lymphohistiocytosis (HLH), cytopenias 603553
(b) UNC13D/Munc13-4 deficiency (FHL3) Mutations in UNC13D a; required to prime vesicles for fusion AR Increased activated T cells Normal Decreased to absent NK and CTL activities (cytotoxicity and/or degranulation) Fever, HSMG, HLH, cytopenias 608898
(c) Syntaxin 11 deficiency (FHL4) Mutations in STX11, required for secretory vesicle fusion with the cell membrane AR Increased activated T cells Normal Decreased NK activity (cytotoxicity and/or degranulation) Fever, HSMG, HLH, cytopenias 603552
(d) STXBP2/Munc18-2 deficiency (FHL5) Mutations in STXBP2, required for secretory vesicle fusion with the cell membrane AR Increased activated T cells Normal Decreased NK and CTL activities (cytotoxicity and/or degranulation) Fever, HSMG, HLH, cytopenias 613101
 1.2. FHL syndromes with hypopigmentation
(a) Chediak–Higashi syndrome Mutations in LYST Impaired lysosomal trafficking AR Increased activated T cells Normal Decreased NK and CTL activities (cytotoxicity and/or degranulation) Partial albinism
Recurrent infections, fever
HSMG, HLH
Giant lysosomes, neutropenia, cytopenias
Bleeding tendency
Progressive neurological dysfunction
214500
(b) Griscelli syndrome, type 2 Mutations in RAB27A encoding a GTPase that promotes docking of secretory vesicles to the cell membrane AR Normal Normal Decreased NK and CTL activities (cytotoxicity and/or degranulation) Partial albinism, fever, HSMG, HLH, cytopenias 607624
(c) Hermansky–Pudlak syndrome, type 2 Mutations in AP3B1 gene, encoding for the b subunit of the AP-3 complex AR Normal Normal Decreased NK and CTL activities (cytotoxicity and/or degranulation) Partial albinism
Recurrent infections
Pulmonary fibrosis
Increased bleeding
Neutropenia
HLH
608233
2. Lymphoproliferative syndromes
(a) SH2D1A deficiency (XLP1) Mutations in SH2D1A encoding an adaptor protein regulating intracellular signaling XL Normal or increased activated T cells Reduced memory B cells Partially defective NK cell and CTL cytotoxic activity Clinical and immunological features triggered by EBV infection: HLH
Lymphoproliferation, aplastic anemia, lymphoma
Hypogammaglobulinemia
Absent iNKT cells
308240
(b) XIAP deficiency (XLP2) Mutations in XIAP/BIRC4 encoding an inhibitor of apoptosis XL Normal or increased activated T cells; low/normal iNK T cells Normal or reduced memory B cells Increased T cells susceptibility to apoptosis to CD95 and enhanced activation-induced cell death (AICD) EBV infection, splenomegaly, lymphoproliferation HLH, colitis, IBD, hepatitis Low iNKT cells 300635
(c) ITK deficiencya Mutations in ITK encoding IL-2 inducible T cell kinase required for TCR-mediated activation AR Progressive decrease Normal Decreased T cell activations EBV-associated B cell lymphoproliferation, lymphoma
Normal or decreased IgG
613011
(d) CD27 deficiencya Mutations in CD27, encoding TNF-R member superfamily required for generation and long-term maintenance of T cell immunity AR Normal No memory B cells Low T and NK cells functions Clinical and immunological features triggered by EBV infection: HLH
Aplastic anemia, lymphoma, hypogammaglobulinemia
Low iNKT cells
615122
3. Genetic defects of regulatory T cells
(a) IPEX, immune dysregulation, polyendocrinopathy, enteropathy X-linked Mutations in FOXP3, encoding a T cell transcription factor XL Normal Normal Lack of (and/or impaired function of) CD4+ CD25+ FOXP3+ regulatory T cells (Tregs) Autoimmune enteropathy
Early-onset diabetes
Thyroiditis, hemolytic anemia, thrombocytopenia, eczema
Elevated IgE, IgA
304790
(b) CD25 deficiencya Mutations in IL-2RA, encoding IL-2Rα chain AR Normal to decreased Normal No CD4+ C25+ cells with impaired function of Tregs cells Lymphoproliferation, autoimmunity. Impaired T cell proliferation 606367
(c) STAT5b deficiencya Mutations in STAT5B, signal transducer, and transcription factor, essential for normal signaling from IL-2 and 15, key growth factors for T and NK cells AR Modestly decreased Normal Impaired development and function of γδT cells, Tregs, and NK cells Low T cell proliferation Growth-hormone insensitive dwarfism 245590
Dysmorphic features
Eczema
Lymphocytic interstitial pneumonitis, autoimmunity
4. Autoimmunity without lymphoproliferation
(a) APECED (APS-1), autoimmune polyendocrinopathy with candidiasis and ectodermal dystrophy Mutations in AIRE, encoding a transcription regulator needed to establish thymic self-tolerance AR Normal Normal AIRE-1 serves as checkpoint in the thymus for negative selection of autoreactive T cells and for generation of Tregs Autoimmunity: hypoparathyroidism hypothyroidism, adrenal insufficiency, diabetes, gonadal dysfunction, and other endocrine abnormalities 240300
Chronic mucocutaneous candidiasis
Dental enamel hypoplasia
Alopecia areata
Enteropathy, pernicious anemia
(b) ITCH deficiencya Mutations in ITCH, an E3 ubiquitin ligase catalyzes the transfer of ubiquitin to a signaling protein in the cell including phospholipase Cγ1 (PLCγ1) AR Not assessed Not assessed Itch deficiency may cause immune dysregulation by affecting both anergy induction in autoreactive effector T cells and generation of Tregs Early-onset chronic lung disease (interstitial pneumonitis) 613385
Autoimmune disorder (thyroiditis, type I diabetes, chronic diarrhea/enteropathy, and hepatitis)
Failure to thrive, developmental delay, dysmorphic facial features
5. Autoimmune lymphoproliferative syndrome (ALPS)
(a) ALPS–FAS Germinal mutations in TNFRSF6, encoding CD95/Fas cell surface apoptosis receptorb AD Increased CD4CD8 TCRα/β double negative (DN) T cells Normal, low memory B cells Apoptosis defect FAS mediated Splenomegaly, adenopathies, autoimmune cytopenias 601859
ARc Increased lymphoma risk
IgG and A normal or increased
Elevated FasL and IL-10, vitamin B12
(b) ALPS– FASLG Mutations in TNFSF6, Fas ligand for CD95 apoptosis AR Increased DN T cells Normal Apoptosis defect FAS mediated Splenomegaly, adenopathies, autoimmune cytopenias, SLE 134638
Soluble FasL is not elevated
(c) ALPS–caspase 10a Mutations in CASP10, intracellular apoptosis pathway AD Increased DN T cells Normal Defective lymphocyte apoptosis Adenopathies, splenomegaly, autoimmunity 603909
(d) ALPS–caspase 8a Mutations in CASP8, intracellular apoptosis, and activation pathways AR Slightly increased DN T cells Normal Defective lymphocyte apoptosis and activation Adenopathies, splenomegaly, bacterial and viral infections, hypogammaglobulinemia 607271
(e) FADD deficiencya Mutations in FADD encoding an adaptor molecule interacting with FAS, and promoting apoptosis AR Increased DN T cells Normal Defective lymphocyte apoptosis Functional hyposplenism, bacterial and viral infections 613759
Recurrent episodes of encephalopathy and liver dysfunction
(f) CARD11 gain-of-function (GOF) mutationsa GOF mutations in CARD11, encoding a protein required for antigen receptor–induced NF-κB activation in B and T lymphocytes AD Normal Increased M+D+CD19+ CD20+ B cells Constitutive activation of NF-κB in B & T Lymphoproliferation 606445
Bacterial and viral infections
EBV chronic infection
Autoimmune cytopenia
Hypogammaglobulinemia
(g) PRKCδ deficiencya Mutations in PRKCD, encoding a member of the protein kinase C family critical for regulation of cell survival, proliferation, and apoptosis AR Normal Low memory B cells and elevation of CD5 B cells Apoptotic defect in B cells Recurrent infections; EBV chronic infection 615559
Lymphoproliferation
SLE-like autoimmunity (nephrotic and antiphospholipid syndromes)
HypoIgG
6. Immune dysregulation with colitis
(a) IL-10 deficiencya Mutations in IL-10, encoding IL-10 AR Normal Normal No functional IL-10 secretion Inflammatory bowel disease (IBD) folliculitis Not assigned
Recurrent respiratory diseases
Arthritis
(b) IL-10Rα deficiency Mutations in IL-10RA, encoding IL-10R1 AR Normal Normal Leukocytes, no response to IL-10 IBD, folliculitis 613148
Recurrent respiratory diseases
Arthritis, lymphoma
(c) IL-10Rβ deficiency Mutations in IL-10RB, encoding IL-10R2 AR Normal Normal Leukocytes, no response to IL-10, IL-22, IL-26, IL-28A, IL-28B, and IL-29 IBD, folliculitis 612567
Recurrent respiratory diseases
Arthritis, lymphoma
7. Type 1 interferonopathies
(a) TREX1 deficiency, Aicardi–Goutieres syndrome 1 (AGS1) Mutations in TREX1, encoding nuclease involves in clearing cellular nucleic debris AR Not assessed Not assessed Intracellular accumulation of abnormal single-stranded (ss) DNA species leading to increased CSF alpha-IFN production Progressive encephalopathy intracranial calcifications 606609
ADe Cerebral atrophy, leukodystrophy
HSMG, thrombocytopenia
Elevated hepatic transaminases
Chronic cerebrospinal fluid (CSF) lymphocytosis
(b) RNASEH2B deficiency, AGS2 Mutations in RNASEH2B, encoding nuclease subunit involves in clearing cellular nucleic debris AR Not assessed Not assessed Intracellular accumulation of abnormal ss-DNA species leading to increased CSF alpha-IFN production Progressive encephalopathy intracranial calcifications 610326
Cerebral atrophy, leukodystrophy
HSMG, thrombocytopenia
Elevated hepatic transaminases
Chronic CSF lymphocytosis
(c) RNASEH2C deficiency, AGS3 Mutations in RNASEH2C, encoding nuclease subunit involves in clearing cellular nucleic debris AR Not assessed Not assessed Intracellular accumulation of abnormal ss-DNA species leading to increased CSF alpha-IFN production Progressive encephalopathy intracranial calcifications 610330
Cerebral atrophy, leukodystrophy
HSMG, thrombocytopenia
Elevated hepatic transaminases
Chronic CSF lymphocytosis
(d) RNASEH2A deficiency, AGS4a Mutations in RNASEH2A, encoding nuclease subunit involves in clearing cellular nucleic debris AR Not assessed Not assessed Intracellular accumulation of abnormal ss-DNA species leading to increased CSF alpha-IFN production Progressive encephalopathy intracranial calcifications 606034
Cerebral atrophy, leukodystrophy
HSMG, thrombocytopenia
Elevated hepatic transaminases
Chronic CSF lymphocytosis
(e) SAMHD1 deficiency, AGS5 Mutations in SAMHD1, encoding negative regulator of the immunostimulatory DNA response AR Not assessed Not assessed Induction of the cell intrinsic antiviral response, apoptosis, and mitochondrial DNA destruction leading to increased CSF alpha-IFN production Progressive encephalopathy intracranial calcifications 612952
Cerebral atrophy, leukodystrophy
HSMG, thrombocytopenia, anemia elevated lactates
Chronic CSF lymphocytosis
Skin vasculitis, mouth ulcers, arthropathy
(f) ADAR1 deficiency, AGS6 Mutations in ADAR1, encoding an RNA-specific adenosine deaminase AR Not assessed Not assessed Catalyzes the deamination of adenosine to inosine in dsRNA substrates markedly elevated CSF IFN-alpha Progressive encephalopathy intracranial calcification Severe developmental delay, leukodystrophy 615010
(g) Spondyloenchondro-dysplasia with immune dysregulation (SPENCD) Mutations in ACP5, encoding tartrate-resistant acid phosphatase (TRAP) AR Not assessed Not assessed Upregulation of IFN-alpha and type I IFN-stimulated genes Recurrent bacterial and viral infections, intracranial calcification 607944
SLE-like autoimmunity (Sjögren’s syndrome, hypothyroidism, inflammatory myositis, Raynaud’s disease and vitiligo), hemolytic anemia, thrombocytopenia, skeletal dysplasia, short stature

XL, X-linked inheritance; AR, autosomal recessive inheritance; AD, autosomal dominant inheritance; FHL, familial hemophagocytic lymphohistiocytosis; HLH, hemophagocytic lymphohistiocytosis; HSMG, hepatosplenomegaly; DN, double negative; SLE, systemic lupus erythematous; IBD, inflammatory bowel disease; CSF, chronic cerebrospinal fluid.

aTen or fewer unrelated cases reported in the literature.

bSomatic mutations of TNFRSF6 cause a similar phenotype (ALPS–sFAS), see Table 9. Germinal mutation and somatic mutation of TNFRSF6 can be associated in some ALPS–FAS patients.

cAR ALPS–FAS patients have a most severe clinical phenotype.

dSomatic mutations in KRAS or NRAS can give this clinical phenotype associated autoimmune leukoproliferative disease (RALD) and are now included in Table 9 entitled phenocopies of PID.

eDe novo dominant TREX1 mutations have been reported.

Fourteen new disorders have been added to Table 4. Two new entries have been added in the table, including immune dysregulation with colitis and Type 1 interferonopathies. EBV-driven lymphoproliferation is also observed in MAGT1 deficiency (Table 1).

The rapid advances in gene identification technology, including the widespread use of whole exome and whole genome sequencing, has meant that the ability to identify gene defects in affected families and even single individuals with inherited diseases has grown enormously. In this report, over 30 new gene defects have been added that were identified since the previous classification in November, 2011. These defects can be found in all major groups of PIDs included in this report. In many cases, the mutations are not necessarily in genes formally implicated in immune cell function but are genes involved in essential cell processes. The more detailed analysis and functional consequences of such defects as illustrated by these PIDs will increase our understanding of the interplay between different cellular processes in the development and function of the immune system.

Among the newly identified, gene defects are many that are to date particular to a single pedigree or individual; such defects may prove exceedingly rare, or indeed may not necessarily be found to recur in other individuals. We have marked conditions for which there are 10 or fewer reported individuals with an asterisk, although historically, following the description of the first few cases, additional individuals with a similar PID phenotype and genotype have often been recognized. It is likely that we will uncover many more “personal” or very rare gene defects over time and that the spectrum of PIDs will become increasingly diverse and complex, due to contributions of both environmental exposures and genetic modifiers to each affected individual. The value of this report therefore to capture and catalog the full spectrum at any one time point becomes increasingly important.

The goal of the IUIS Expert Committee on PIDs is to increase awareness, facilitate recognition, and promote optimal treatment for patients with PIDs. In addition to the current report and previous “classification table” publications, the committee has also produced a “Phenotypic Approach for IUIS PID Classification and Diagnosis: Guidelines for Clinicians at the Bedside,” which aims to lead physicians to particular groups of PIDs starting from clinical features and combining routine immunological investigations. Together, these contributions will hopefully allow a practical clinical framework for PID diagnosis. The committee also aims to establish a classification of PIDs based on other aspects and will work on publishing further guidelines in due course.

Conflict of Interest Statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


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