A recent study identified over forty regions of the human genome that govern the age a woman goes through menopause. The study found that two thirds of these regions contain genes that act to keep DNA healthy, by repairing the small damages that tend to accumulate with age. The study also found the first genetic evidence of a link between the timing of menopause and breast cancer. The results were published in the journal Nature Genetics on Sept. 28, 2015.
The timing of menopause affects infertility and risk of disease (i.e., breast cancer), but the underlying mechanisms are poorly understood. Women who experience menopause before the age of 40 are less likely to develop breast cancer but more likely to develop other complications such as osteoporosis, cardiovascular disease, and type 2 diabetes. Genetics has a role in determining the age of natural menopause, but the full spectrum of genes involved and how they contribute to these other risks is not known. This current study increases our understanding of how reproductive aging happens. This could lead to the development of new treatments to avoid early menopause, which may potentially improve fertility and decrease breast cancer risk. Such developments would be of interest and may impact the female population in Connecticut, who make up 51.3 percent of Connecticut’s population (that’s over 1.83 million people).
Researchers performed a genome-wide association study with nearly 70,000 women and identified genetic variants associated with age at menopause. These variants were enriched in genes involved in repairing damaged DNA and in genes linked to primary ovarian insufficiency and delayed puberty. These findings suggest potential molecular links between the onset and end of the female reproductive lifespan. In addition, the study also found evidence that genetic variants leading to later menopause also increase breast cancer risk.
“We have known for some time that the age at which women go through menopause is partly determined by genes. This study now tells us that there are likely hundreds of genes involved, each altering menopause age by anything from a few weeks to a year. It is striking that genes involved in DNA repair have such an important influence on the age of menopause, which we think is due to their effect on how quickly a woman’s eggs are lost throughout her lifetime,” said John Perry, Ph.D. who co-led the study.
Anna Murray, Ph.D., senior author on the paper, describes the impact of the study’s findings:
”Many women today are choosing to have babies later in life, but they may find it difficult to conceive naturally because fertility starts to diminish at least 10 years before menopause. Our research has substantially increased our understanding of how reproductive aging in women happens, which we hope will lead to the development of new treatments to avoid early menopause.”
Future research will help understand in more detail how the genetic variations found in this study are causing alterations in the timing of menopause. Uncovering these mechanisms may lead to better treatment for conditions linked to menopause (such as infertility) and lead to improved understanding of the heath impact of menopause (such as risk of osteoporosis and heart disease).