Polymorphic CAG repeat numbers in the androgen receptor gene of female pattern hair loss patients.

Female pattern hair loss (FPHL) is frequently referred to as female androgenetic alopecia (FAGA). However, the role of androgen in this type of hair loss remains uncertain. We previously reported greater therapeutic efficacy of finasteride in Japanese male androgenetic alopecia (MAGA) patients in cases where the CAG repeats of the androgen receptor (AR) gene were short. To examine the correlation between CAG repeat numbers and the therapeutic efficacy of finasteride in FPHL patients, the efficacy of finasteride (1 mg/day) was evaluated macroscopically. Because women have two X-chromosomes, the shorter and longer CAG repeat numbers were analyzed in 37 Japanese FPHL patients, then the correlation of these factors was statistically analyzed by anova. No statistical significance in terms of the differences in CAG repeat numbers was detected among the four groups classified on the basis of the efficacy of finasteride. From these results, it may be concluded that the efficacy of this medicine in each FPHL patient cannot be predicted by the CAG repeat numbers in the AR gene.