Carriers of 21-Hydroxylase Deficiency Are Not at Increased Risk for Hyperandrogenism

In a 1997 study involving 38 carriers of CYP21 mutations and 27 matched controls, researchers found that while carriers had higher mean total and free testosterone levels and lower sex hormone-binding globulin levels, these biochemical differences did not result in a higher prevalence of clinically evident hyperandrogenism. The study concluded that heterozygosity for CYP21 mutations does not significantly increase the risk of clinical androgen excess. Despite higher stimulated 17-hydroxyprogesterone levels in carriers, only 10.5% exhibited functional androgen excess, which was not significantly different from the general population. The study also noted that the frequency of CYP21 mutations in hyperandrogenic patients was not significantly greater than in the general population, and the sample was derived from specific regions in France and the U.S., which may not be representative of the larger population.