Genes decide when menopause arrives

Posted May 26, 2009 by Kathlyn Stone
Teams of scientists led by Netherlands and U.S. investigators have identified genetic variants which affect the age when a woman reaches menopause.
Part of a DNA strand
DNA strand.
Until now, the mechanisms that brought on menopause were unknown, but heredity was long suspected.
Now researchers that led two separate studies conclude that changes in a woman's genetic code may influence the ovaries or the brain, triggering the change.
In the first study, a team of researchers at Erasmus University in Rotterdam, the Netherlands, gathered genetic data from nine studies involving 10,339 menopausal women. During analysis they found 20 changes, or genetic variations, in individuals' genetic codes that were associated with early menopause. The genetic variants, called single nucleotide polymorphisms (SNPs), are located at four different sites on chromosomes 19 and 20.
Lisette Stolk, one of the investigators, told the BBC, "We found that the 20 SNPs were all related to a slightly earlier menopause, and women who had one of them experienced menopause nearly a year earlier than others.
"We know that 10 years before menopause women are much less fertile, and five years before many are infertile.
"In Western countries, where women tend to have children later in life and closer to menopause, age at menopause can be an important factor in whether or not a particular woman is able to become a mother."
The Erasmus University findings were presented May 25 at the annual meeting of the European Society of Human Genetics in Vienna.
In the second study, researchers from Harvard School of Public Health, Brigham and Women's Hospital, National Cancer Institute, and the Broad Institute of Harvard and MIT, analysed more than 317,000 gene variants in 17,438 women to see if they could identify genetic links to the onset of menstruation and menopause. Their investigation, reported May 26 in Nature Genetics found 10 genetic variants in two chromosomal regions associated with age at menarche (the first menstrual period), and 13 genetic variants in four chromosomal regions associated with age at menopause.
Results from both studies could have implications for improved treatments for infertility, breast and endometrial cancer, osteoporosis, and cardiovascular disease.