A distinct gene close to the hairless locus on chromosome 8p underlies hereditary Marie Unna type hypotrichosis in a German family

Background Hypotrichosis of the Marie Unna type (HMU) is a rare autosomal dominant disorder characterized by male-pattern hair loss with childhood onset and anomalies of the hair shaft. Objectives We aimed to evaluate a number of chromosomal loci as possible candidate regions for HMU. Methods A linkage analysis was performed in a large German family using microsatellite markers spanning candidate regions on chromosomes 8, 12 and 17. Results We found that the HMU locus maps to chromosomal region 8p21 in a 13.01-cM interval between markers D8S1145 and D8S1771. This interval harbours the hairless gene (HR). Mutational analysis of HR on the genomic and transcript levels revealed no pathogenic mutation. Conclusions Our findings, together with a recent report of two unrelated families of Dutch and British origin, provide evidence for a hair growth regulatory gene distinct from HR in chromosomal region 8p21.