Table 2.
Monogenic inflammatory bowel disease (IBD) variants that can be present in adults
| Type | Phenotype | Associated features | Lab abnormalities |
|---|---|---|---|
| LRBA and ICOS | UC/CD | Recurrent infections, hepatosplenomegaly, lymphadenopathy | Hypogammaglobulinemia |
| XIAP (XLP2) | Crohn's‐like granulomatous colitis in males |
Perianal fistula; HLH; Splenomegaly; Cholangitis; Skin abscesses; Arthritis, EBV and CMV infections; |
Hypogammaglobinemia |
|
CGD CYBB CYBA NCF1 NCF2 NCF4 |
Crohn's‐like colitis |
Recurrent infections for catalase‐positive organisms; Perianal fistula; Gastric outlet obstruction; Eczema |
Decreased neutrophil oxidative burst study; Elevated IgG |
| LAD1 (ITGB2) | Crohn's‐like with stenosis/stricturing phenotype |
Neutrophilia Recurrent infections Delayed separation of umbilical cord; Poor wound healing; Folliculitis; Ulcers of skin; Peridontitis; Gingivitis |
Absent CD11/CD18 complex expression |
| SLCO2A1 | Small‐bowel stricturing disease | Primary hypertrophic osteoarthropathy | — |
| PLA2G4A | Small‐bowel stricturing disease | — | — |
| WAS | UC‐like colitis in males |
Thrombocytopenia; Atopic dermatitis; Autoimmune hemolytic anemia; Arthritis; Bacterial/viral infections; Lymphoreticular malignancy |
Microthrombocytopenia; Variable lymphopenia; Absent class‐switched memory B‐cells; High IgE; Low IgG, IgA, and IgM |
| CD 55 (CHAPEL syndrome) | Enterocolitis with ulcers in terminal ileum |
Early‐onset, protein‐losing enteropathy; Primary intestinal obstruction; Edema; Malabsorption; Recurrent infections; Angiopathic thromboemboli |
Absent CD55 expression on lymphocytes |
| G6P3C | Crohn's‐like with strictures; Oral and genital aphthous ulcerations |
Cutaneous vascular malformation; Cardiac defects; Urogenital developmental defects; Bleeding tendency |
Severe neutropenia; T‐cell lymphopenia; Elevated IgG |
| SLC37A4 |
Crohn's‐like colitis with ulcerations; Strictures; Perianal fistula |
Hepatosplenomegaly; Nephrocalcinosis; Folliculitis |
Neutropenia and/or neutrophil dysfunction with predisposition to infections; Hypoglycemia; Hyperuricemia; Hyperlipidemia |
| SLC9A3 and GUCY2C (congenital sodium diarrhea) | IBD‐like small intestinal involvement in adults | Elevated liver enzymes and cholestasis |
High stool sodium levels Low serum sodium levels, Metabolic acidosis, Alkaline fecal pH, Low urinary sodium excretion |
CD, Crohn's disease; HLH, hemophagocytic lymphohistiocytosis; UC, ulcerative colitis.