Marie Unna hereditary hypotrichosis: report of a Chinese family and evidence for genetic heterogeneity.

Marie Unna hereditary hypotrichosis (MUHH) is a rare autosomal dominant disorder with progressive hair loss starting in early childhood and aggravating at puberty. Several studies have mapped the MUHH gene to chromosome 8p21. Here we report a Chinese MUHH family with variable phenotypes. All affected individuals have anomalies affecting both hair density and hair shafts. Major clinical characteristics, disease history and histological examination support the diagnosis of MUHH, but the features of scarring in this kindred are modest and none of the patients have vertex hair loss, which is in contrast with typical MUHH. We now report genotyping and linkage analysis using 11 polymorphic microsatellite markers spanning the MUHH locus at 8p. Two-point linkage analysis using these markers revealed significant exclusion of this locus (log of the odds scores < - 2) at Theta = 0 indicating that there is a range of clinical presentations in MUHH, and that more than one genetic locus is responsible for the disorder.