Atrichia with papular lesions resulting from compound heterozygous mutations in the hairless gene: A lesson for differential diagnosis of alopecia universalis

Abstract

Background: Atrichia with papular lesions (APL) is a rare, autosomal recessive form of total alopecia in which mutations in the hairless (HR) gene have been shown to underlie the phenotype. Objective: We suspect that APL is actually much more common than previously believed. We sought to investigate whether APL might also be found among patients in small families, particularly those giving a history of (1) normal hair at birth, which was shed and never regrew, and (2) “alopecia universalis” that is recalcitrant to any treatment. Methods: We identified a small family of German origin in which 2 of 4 siblings were affected and gave this clinical history. Direct sequence analysis of the HR gene in the nuclear family was performed. Results: Mutation analysis revealed distinct mutations on each allele of the HR gene. This is the first demonstration of compound heterozygous mutations underlying APL. Conclusion: These findings support the hypothesis that APL can exist in small nonconsanguineous families and may be masquerading clinically as alopecia universalis. Accurate discrimination between APL and alopecia universalis should prevent unnecessary treatment of patients affected with APL.