Genetics of polycystic ovary syndrome

We have found evidence for the involvement of two major genes in the aetiol ogy of PCOS. The results of both linkage and association studies suggest th at CYP11a (coding for P450 cholesterol side chain cleavage) and the insulin VNTR regulatory polymorphism are important genes in the aetiology of PCOS and may explain, in part, the heterogeneity of the syndrome. Differences in expression of CYP11a could account for variation in androgen production in women who have polycystic ovaries and those subjects who are homozygous fo r III alleles at the insulin gene VNTR locus are more likely to be hyperins ulinaemic. It is likely that other genes are involved in the aetiology of P COS. Recent results lend weight to the idea that PCOS represents a complex trail in which several genes-but perhaps a relatively small number of key g enes-contribute, in conjunction with nutritional factors, to the observed c linical and biochemical heterogeneity. (C) 1998 Published by Elsevier Scien ce Ireland Ltd. All rights reserved.