The prevalence of non-classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency in Russian women with hyperandrogenism.

The aim of the study was to determine the prevalence of non-classic congenital adrenal hyperplasia (NCAH) due to 21-hydroxylase (21-OH) deficiency among hyperandrogenic women in a Russian population and to evaluate diagnostic value of basal serum 17-hydroxyprogesterone (17-OHP) level to diagnose this disease. A total of 800 consecutive Caucasian women presenting with elevation of at least one serum androgen and/or manifestation of one of the clinical androgenic symptoms were prospectively recruited and evaluated by basal 17-OHP. The diagnosis of NCAH due to 21-OH deficiency was considered in patients when basal level exceeded 5.0 nmol/L and CYP21A2 gene mutation analysis was performed in this case. Eight (1.0%) of the patients had NCAH due to 21-OH deficiency confirmed by genotyping. These women had a V281L mutation: five homozygous and three compound heterozygous with genotypes V281L/P453S, V281L/I2splice and V281L/I2splice. One patient was diagnosed with NCAH (genotype V281L/I2splice) before the study and was excluded from the analysis. Thus, the unbiased prevalence of NCAH was 0.9%. The 17-OHP basal level ranges from 16.8 to 17.7 nmol/L predicted NCAH with 100% sensitivity and 100% specificity.