PCOS Twin Study - Environmental Factors in the Development of Polycystic Ovary Syndrome, Phase 2

Study Summary

Polycystic Ovary Syndrome, or PCOS, is the most common endocrine disorder in women. Depending on the strictness of the diagnostic criteria used, it is thought to occur in about 6-10% of all women, many of whom do not know they have the syndrome. Women with PCOS produce abnormally high levels of male hormones (hyperandrogenism); this counteracts their ovaries' ability to make enough of the female hormones estrogen and progesterone needed for normal menstruation. PCOS is the number one cause of hormonally related infertility and also increases women's risks for diabetes, high blood pressure, hypercholesteremia, cardiovascular disease and certain cancers. It is currently unclear to what extent PCOS and PCOS-associated traits (hyperandrogenisms, hyperinsulinemia, insulin resistance, type 2 diabetes, dyslipidemia, hypertension, obesity, and coronary artery disease) are the results of environmental factors or genetic predisposition. Therefore, the NIEHS Program in Clinical Research is conducting a multi-phase twin study to measure the extent of PCOS heritability and to identify environmental and genetic factors involved in the development of PCOS. The proposal described here is for Phase 2 of this study. The goals of Phase 2 are to: 1) establish more reliable concordance rates and baseline heritability estimates for PCOS in MZ and DZ twins; and 2) establish a cohort of intact MZ and DZ female twin pairs as a resource for future studies. In Phase 1, about 1500 individual female twins were identified from the Mid-Atlantic Twin Registry (MATR) based on self report of a history of irregular periods and/or cystic ovaries in the MATR General Health Screening Questionnaire. Those twins were surveyed by phone for other traits associated with PCOS. In Phase 2, the twins most likely to have PCOS based on their answers to the Phase 1 phone survey will be recontacted for further PCOS screening. This includes providing a blood sample for measuring bioavailable testosterone (BaT) leve