Search for susceptibility genes in alopecia areata.

Alopecia areata (AA) is a multifactorial disorder, in which genetic and environmental factors combine to result in the phenotype (Green and Sinclair, 2000). The prognosis of AA is unpredictable and there is no definitive treatment. Several lines of evidence support the polygenic inheritance of AA, including the high prevalence of the trait, the Gaussian curve of distribution of the phenotype, and heritability among first-degree relatives (Aita and Christiano, 2001). Genetic studies have been limited to association analyses, which suggest that a permissive HLA status may potentiate the development of AA (Welsh et al, 1994).