Variants in the 5alpha-reductase type 1 and type 2 genes are associated with polycystic ovary syndrome and the severity of hirsutism in affected women.

Genetic evidence is presented suggesting an important role of both isoforms of 5alpha-reductase in the pathogenesis of PCOS and that only SRD5A1 haplotypes were associated with hirsutism, suggesting that only this isoform is important in the hair follicle.