The role of heterozygosity for CYP21 in the polycystic ovary syndrome

Abstract

The phenotypic heterogeneity recognized in congenital adrenal hyperplasia secondary to 21-hydroxylase deficiency appears to extend to 21hydroxylase (CYP21) mutation carriers. To begin the search for modifying loci responsible for this phenotypic heterogeneity, we performed CYP21 genotype analysis and assays for three candidate modifier loci on genomic DNA samples obtained from 30 adolescent girls with hyperandrogenism, 14 healthy control women, and 15 female obligate CYP21 mutation carriers. The frequency of heterozygosity for CYP21 mutations was increased in women with symptomatic hyperandrogenism (10/30) compared to healthy controls (1/14). There were no significant differences in the frequencies of the modifier variants among the three groups. Although the small sample size precludes strong conclusions, CYP21 nonsense mutation carriers tend to be asymptomatic while missense mutation carriers, i.e. V281L, appear to manifest a PCOS phenotype. Evaluation of additional modifying loci in larger series of patients will help identify new genetic markers associated with PCOS.