Price et al. (1980) suggested the designation trichothiodystrophy (TTD) to describe brittle hair with reduced sulfur content. The disorder bears some resemblance to that reported in the Amish and called here hair-brain syndrome (234050). Also see Netherton syndrome ... Price et al. (1980) suggested the designation trichothiodystrophy (TTD) to describe brittle hair with reduced sulfur content. The disorder bears some resemblance to that reported in the Amish and called here hair-brain syndrome (234050). Also see Netherton syndrome (256500) and Tay syndrome (601675). Trichorrhexis nodosa also occurs in argininosuccinicaciduria (207900), in Menkes disease (309400), and in biotin deficiency. Trichorrhexis nodosa syndrome, also called Pollitt syndrome, is a form of nonphotosensitive trichothiodystrophy; see 234050. Pollitt et al. (1968) described a brother and sister with mental and physical retardation and trichorrhexis nodosa. Microcephaly and abnormal cerebral cortical cell layering were associated with reduction in the content of high sulfur protein in hair. Cystine content of the hair was about half normal (Pollitt and Stonier, 1971). King et al. (1984) described 2 cases in unrelated children. The first, a boy, showed at birth short, woolly hair that fell out easily. At 6 months he was first seen for developmental delay. The length, weight, and head circumference were below the 3rd centile. The face was unusual with receding chin and protruding ears. The skin was ichthyotic with severe flexural eczema. The hairs of the eyebrows were stubby, but the eyelashes were normal. The nails were hypoplastic and spoon-shaped. Neurologic findings included jerky ocular pursuit movements with titubation of the head, spastic diplegia, extensor plantar reflexes, and absent deep tendon reflexes. The findings were virtually identical at age 4. In addition, the skin was highly photosensitive. The findings in the second case, in a female child, were nearly identical except that bilateral central nuclear cataracts, hyperactive deep tendon reflexes, adductor spasm and scissoring of the lower limbs were noted. Both children were the product of unrelated Scottish parents. King et al. (1984) suggested that this disorder is the same as the Amish brittle hair syndrome and the Sabinas brittle hair syndrome (211390).
In 2 cases of Sabinas syndrome and 1 case of Pollitt syndrome, Nakabayashi et al. (2005) failed to find mutation in the C7ORF11 gene (609188), mutations in which were found in other nonphotosensitive TTD cases with mental retardation ... In 2 cases of Sabinas syndrome and 1 case of Pollitt syndrome, Nakabayashi et al. (2005) failed to find mutation in the C7ORF11 gene (609188), mutations in which were found in other nonphotosensitive TTD cases with mental retardation and decreased fertility (see 234050). The authors suggested that genetic heterogeneity in nonphotosensitive TTD is a feature similar to that observed in photosensitive TTD, which is caused by mutation in transcription factor TFIIH genes (see 601675).