Although the average age of menopause is 51 years, approximately one per cent of women will experience menopause before the age of 40, a condition known as premature ovarian failure. Working on the hypothesis that multiple genetic factors may combine and interact in a single individual to determine the rate of reproductive aging, Karla Bretherick is examining the molecular genetic differences between women with normal reproductive function and women with premature ovarian failure. She hopes her work identifying specific genetic factors that contribute to early menopause may lead to the development of both treatment options for affected individuals and predictive testing for those at risk.