When is the best time to start a family? In making this decision, each woman must weigh external factors against her internal biological clock. In Caucasian women, menopause occurs around 51 years of age, with a normal range between 40 and 60 years. Although post-menopausal infertility is widely recognized, many women may not know that they are at risk for infertility the decade before menopause as well. With more women delaying childbirth, a need exists for long-term indicators to allow women to make more informed reproductive decisions well in advance of menopause onset.
Studies have shown that the timing of menopause has a genetic component and four SNPs have already been linked to age of onset. In a study published last week, Anne Murray and her colleagues from the University of Exeter explored whether these SNPs also influence risk of menopause occurring before age 46 (early menopause) in a group of 4000 Caucasian women (~2000 with early menopause, ~2000 with normal menopause age). Based on their findings, the authors suggest that all four SNPs are associated with an elevated risk of a younger menopause age. The number of risky versions present is also important, where more variants means higher early menopause odds.
Using the Browse Raw Data feature, 23andMe customers can assess their risk of early menopause from the rs16991615 SNP located on chromosome 20. Although our database includes only one of the four SNPs from the study, rs16991615 shows significant impact on early menopause risk. The authors found that the rarer A version of rs16991615 (present in only 7% of the population) is protective, with each copy associated with 46% lower odds of early menopause. Murray’s team also tested the association of the “menopause SNPs” with cases of very early menopause (< age 40), termed premature ovarian failure (POF). Surprisingly, they found that rs16991615 has less of an influence on POF than on the risk of just “early” menopause (age 40-45).
The average age of first-time mothers has risen steadily over the last four decades, due, in part, to the eight-fold increase in the number of women entering motherhood over age 35. The authors suggest that genetic testing for early menopause could provide younger women with a better defined range of their childbearing years. Of course, women must consider many factors when deciding to start a family and the current predictive power of known SNPs is too limited to override other important life choices. However, as more SNPs are discovered and their role in menopause becomes better understood, genetic testing for early menopause risk may eventually be useful for some women.
SNPwatch gives you the latest news about research linking various traits and conditions to individual genetic variations. These studies are exciting because they offer a glimpse into how genetics may affect our bodies and health; but in most cases, more work is needed before this research can provide information of value to individuals. For that reason it is important to remember that like all information we provide, the studies we describe in SNPwatch are for research and educational purposes only. SNPwatch is not intended to be a substitute for professional medical advice; you should always seek the advice of your physician or other appropriate healthcare professional with any questions you may have regarding diagnosis, cure, treatment or prevention of any disease or other medical condition.