Objective: To investigate the frequency of T-->C substitution (-34 bp) of gene CYP17 promoter in Greek patients with polycystic ovary syndrome (PCOS) and to elucidate its role in the pathogenesis of the syndrome.
Design: Follow-up study.
Setting: Academic research setting.
Patient(s): Fifty patients with PCOS and 50 healthy women.
Intervention(s): Body mass index and the waist-hip ratio were determined for each woman. Blood samples were obtained for DNA analysis and hormone estimates.
Main outcome measure(s): Serum total T levels.
Result(s): Seventeen patients (34%) did not carry the base pair substitution (genotype A1A1) and their mean (+/- SD) total T level was 75.7+/-32.2 ngl/dL, 29 patients (58%) were heterozygous carriers of the A2 allele (genotype A1A2) and their mean total T level was 77.8+/-29.9 ng/dL, and 4 patients (8%) carried the A2 allele in homozygosity (genotype A2A2) and their mean total T level was 87.0+/-2.8 ngl/dL. Twenty-two controls had the genotype A1A1 (44%) and their mean total T level was 39.1+/-15.5 ng/dL, whereas 28 (56%) had the genotype A1A2 and their mean total T level was 44.9+/-22.1 ng/dL. Homozygosity of the polymorphic A2 allele was not observed in controls, and this difference (8% versus 0%) was statistically significant.
Conclusion(s): Although this base pair substitution is not the primary genetic defect in PCOS, it may aggravate the clinical picture of hyperandrogenemia, particularly when homozygosity exists.