Table 1.
Pili torti in genetic diseases and syndromes.
| Disease/Syndrome | Genetic Defect, Inheritance | Other Clinical Findings | Other Hair Shaft Abnormalities |
|---|---|---|---|
| Abnormal hair, joint laxity, and developmental delay [14,15] | HEPHL1 gene (AR) | growth and developmental delay, joint laxity, neurologic abnormalities | trichorrhexis nodosa |
| Acrofacial dysostosis, Palagonia type [16] |
NK (AD) | short stature, vertebral anomalies, syndactyly, oligodontia, cleft lip | - |
| Arginosuccinic aciduria [17] | ASL gene (AR) | lethargy, vomiting, seizures, cerebral edema, hepatomegaly | trichorrhexis nodosa |
| Autosomal recessive ichthyosis with hypotrichosis [18] | ST14 gene (AR) | lamellar ichthyosis, follicular atrophoderma, hypohidrosis | dysplastic hair, pili bifurcati |
| Bazex-Dupre-Christol syndrome [19] | ACTRT1 gene (XD) | follicular atrophoderma, multiple basal cell carcinomas, milia, hypohidrosis | trichorrhexis nodosa |
| Björnstad syndrome [20,21] | BCS1L gene (AR, AD) | sensorineural hearing loss | - |
| Citrullinemia [22] | ASS1 gene (AR) | hyperammonemia, lethargy, poor feeding, vomiting, high intracranial pressure, scaly skin eruption | trichorrhexis nodosa |
| Congenital disorder of glycosylation, type Ia [23] |
PMM2 gene (AR) | hypotonia, strabismus, cerebellar hypoplasia, seizures, mental and physical retardation, hepatomegaly, liver fibrosis, fat pads, ‘orange peel’ skin | trichorrhexis nodosa |
| Congenital erythropoietic porphyria [24] | UROS gene (AR) | severe skin photosensitivity (scarring, blistering), erythrodontia, reddish-colored urine, anemia |
- |
| Congenital hypotrichosis with juvenile macular dystrophy [25] | CDH3 gene (AR) | retinal degeneration | - |
| Conradi-Hünermann syndrome [26] | EBP gene (XD) | short stature, asymmetric short limbs, vertebral malformations, hip dysplasia, chondrodysplasia punctata, follicular atrophoderma, abnormal nails, craniofacial anomalies, cataracts | - |
| Crandall syndrome [27] | NK (AR) | neurosensory deafness, hypogonadism with decreased levels of luteinizing hormone and growth hormone |
- |
| Giant axonal neuropathy [28] | GAN gene (AR) | progressive sensorimotor peripheral neuropathy, axonal loss, optic atrophy, ophthalmoplegia, skeletal deformations | trichorrhexis nodosa |
| Hypotrichosis 6 [29,30] | DSG4 gene (AR) | hyperkeratotic follicular papules, erythema, scaling, dry skin |
monilethrix-like hair, trichoschisis, trichorrhexis nodosa-like defects, tapered hair |
| Laron syndrome [31] | GHR gene (AR) | short stature, obesity, facial dysmorphism, hypogenitalism, elevated serum growth hormone, undetectable or low serum insulin-like growth factor 1 | - |
| Marie Unna hypotrichosis [32] | U2HR gene (AD) | - | - |
| McCune-Albright syndrome [33] | GNAS1 gene (not inherited) | polyostotic fibrous dysplasia, cafe-au-lait skin pigmentation, multiple endocrine dysfunction | - |
| Menkes disease [5] | ATP7A gene (XR) | growth retardation, vascular, neurological, and skeletal abnormalities, pale skin | trichoclasis, trichorrhexis nodosa, trichoptilosis |
| Mitochondrial diseases [34] | all modes of inheritance can be expected | mental retardation, failure to thrive, hypotonia, hypoparathyroidism | longitudinal grooving with cuticle loss |
| Netherton syndrome [35,36] | SPINK5 gene (AR) | congenital erythroderma, atopic manifestations, increased IgE level | trichorrhexis I vaginata, trichorrhexis nodosa, trichoschisis, trichoptilosis |
| Occipital horn syndrome [37] | ATP7A gene (XR) | tallness, pectus excavatum, dorsal kyphosis, occipital horn exostoses, joint laxity, loose skin, decreased serum copper and ceruloplasmin | - |
| Olmsted syndrome [38] | TRPV3 gene (AD) | constriction of digits (‘pseudoainhum’), mutilating palmoplantar keratoderma, onychodystrophy, periorificial keratotic plaques | trichorrhexis nodosa |
| Peeling skin syndrome [39] | CDSN gene (AR) | superficial patchy peeling of the entire skin, erythroderma, atopy, nail anomalies | trichorrhexis invaginata-like changes, monili-form hair shaft diameter reductions, irregular hair shaft torsions |
| Salti-Salem syndrome [40] | NK (AD) | hypogonadotropic hypogonadism | - |
| Steatocystoma multiplex [41] | KRT17 gene (AD) | subcutaneous cysts | pili canaliculi |
| Tricho-hepato-enteric syndrome [42] | TTC37, SKIV2L genes (AR) | low birth weight, failure to thrive, facial dysmorphism, diarrhoea, liver disease | trichorrhexis nodosa, aniso- and poilkilotrichosis |
| Trichothiodystrophy, photosensitive [43,44] | ERCC2, XPD genes (AR) | mental and physical retardation, short stature, facial dysmorphism, ichthyosis, photosensitivity, ocular abnormalities | Pili annulati (‘tiger-tail’ hair), trichoschisis, trichorrhexis nodosa |
AD, autosomal dominant; AR, autosomal recessive; NK, not known; XD, X-linked dominant; XR, X-linked recessive.