[Mutation of the human hairless gene in atrichia universalis]

Recently a mutation of the human homologue of the murine hairless gene on chromosome 8p12 has been demonstrated in a Parkistani kindred with autosomal recessive atrichia universalis. Of the various forms of hereditary human hair loss, collectively and incorrectly termed alopecias, congenital universal alopecia, or rather atrichia, represents a rare disease which has nothing to do with the most frequent causes of hair loss, specifically androgenetic alopecia (AGA) and alopecia areata (AA). It may preferably be referred to as generalized atrichia, since alopecia universalis is also the term used for the most extreme form of disease progression in AA leading to complete loss of scalp and body hair. Interestingly the hairless mouse has formerly been proposed to be the animal model for atrichia with papular lesions (papular atrichia), which is likewise transmitted as an autosomal recessive trait. In contrast to these rare forms of hereditary atrichia with a Mendelian pattern of inheritance, both AGA and AA are considered to be polygenic, with hormonal and immunologic factors, respectively, modifying the phenotypic expression. Nevertheless, pinpointing a gene that encodes a transcription factor involved in hair growth may provide a more targeted approach to treat disorders of hair growth through transcriptional control of a variety of cytokines and growth factors implicated in the hair growth cycle.