Uncombable Hair Syndrome 3

A number sign (#) is used with this entry because of evidence that uncombable hair syndrome-3 (UHS3) is caused by homozygous mutation in the TCHH gene (190370) on chromosome 1q21. One such patient has been reported.

Description

Uncombable hair syndrome is characterized by silvery, blond, or straw-colored scalp hair that is dry, frizzy, and wiry, has a characteristic sheen, stands away from the scalp in multiple directions, and is impossible to comb. This hair shaft disorder occurs in children and improves with age. The hair growth rate can range from slow to normal (summary by U. Basmanav et al., 2016).

For a general phenotypic description and a discussion of genetic heterogeneity of UHS, see UHS1 (191480).

Clinical Features

U. Basmanav et al. (2016) reported a 19-year-old German woman who presented to clinic with the complaint that her hair grew too slowly. Her hair was otherwise healthy. The woman reported that she had brittle, curly hair, which was barely combable, until the age of 14 years.

Molecular Genetics

In a 19-year-old German woman with uncombable hair syndrome, U. Basmanav et al. (2016) identified a homozygous mutation in the TCHH gene (190370.0001). The mutation was found by whole-exome sequencing and confirmed by Sanger sequencing. Functional studies of the variant were not performed.