Compound heterozygosity for mutations in the hairless gene causes atrichia with papular lesions.

Abstract

Congenital atrichias represent a complex and heterogeneous group of genodermatoses, which have been shown in several consanguineous families to result from homozygous mutations in the hairless gene (HR). To identify the molecular basis of congenital atrichia in a non-consanguineous family. Genetic analysis was carried out in a two-generation family with two children with congenital atrichia and one healthy child. We established a diagnosis of atrichia with papular lesions based on clinical and histopathological data. We identified a heterozygous 11-bp deletion (189-199del) in the two affected children and their mother. In addition, the two affected children and their father were shown to carry a non sense mutation (Q478X), which has previously been described in a Pakistani family. Haplotype analysis revealed that mutation Q478X occurred independently in the two families. We have identified the first case of compound heterozygosity for mutations in HR as well as the first instance of a recurrent mutation in this gene. These data further expand our understanding of the molecular pathomechanisms underlying congenital atrichias.