Frequency of a polymorphism in the regulatory region of the 17 alpha-hydroxylase-17,20-lyase (CYP17) gene in hyperandrogenic states

OBJECTIVE Dysregulation of 17 alpha-hydroxylase (CYP17) has been proposed as a cause of hyperandrogenism. We have determined the prevalence of a polymorphic allele in the CYP17 gene in sporadic patients with polycystic ovaries (PCOS) compared to a reference population, and to a group of hyperandrogenic individuals, to assess its significance to androgen production. PATIENTS AND DESIGN DNA was isolated from EDTA blood samples from 69 patients with PCOS, 63 patients with congenital adrenal hyperplasia secondary to 21-hydroxylase deficiency and 124 consecutive patients attending for a full blood examination. The thymine (T) to cytosine (C) polymorphism at -34 base pairs (bp), denoted alleles A1 and A2 respectively, was detected by amplification of DNA followed by restriction enzyme digestion. MEASUREMENTS Testosterone and LH. The frequency of alleles A1 and A2 in each of the subject groups was determined. RESULTS The prevalences of the A1 and A2 alleles were 75 and 25% respectively in the PCOS group which was not significantly different from that in either the hyperandrogenic or the reference group. Neither allele segregated with hyperandrogenism. CONCLUSION The polymorphism plays no apparent role in the dysregulation of CYP17.