Atrichia with papular lesions maps to 8p in the region containing the human hairless gene.

Atrichia with papular lesions (APL) (OMIM 209500) is a hereditary form of alopecia. Hair loss occurs soon after birth and is followed years later by the development of a diffuse papular eruption. Its mode of transmission is still uncertain. A related but clinically distinct form of alopecia, known as alopecia universalis (OMIM 203655), has recently been found to be associated with a mutation in the human hairless gene. The present report describes the largest consanguineous kindred of APL reported to date and provides strong evidence for autosomal recessive inheritance of this rare disorder. On the basis of a linkage analysis of this kindred using six microsatellite markers spanning the human hairless gene region, we found that the APL locus maps to chromosome region 8p12 in a 5 cM interval between marker D8S560 and marker D8S1739. A maximum lodscore of 3.7 was obtained with marker D8S1786, at a recombination fraction of 0. Our results suggest phenotypic variability at the hairless locus although they do not rule out the existence of a gene cluster associated with hair disorders in the same region.