January 24, 2012
Study Finds Genetic Links To Onset Of Menopause
Researchers have discovered 13 genetic locations that affect the age of onset of menopause, shedding light on the biological pathways involved in reproductive lifespans and providing new insight into conditions connected to menopause, such as breast cancer and heart disease.
Menopause -- the cessation of reproductive function of the ovaries -- is a major hormonal change that affects most women when they are in their early 50s. The timing of menopause can have an enormous impact on fertility, and can influence the risk of diseases such as breast cancer.
It has long been known that genetic factors played a role in the onset of menopause. However, until recently, very few genes had been identified since most prior studies focused on genes from the estrogen-production pathway or vascular components.
In the current study, an international team of researchers uncovered 13 novel genetic loci, and confirmed four previously established loci, which are linked to the age of onset of menopause.
Most of the 17 loci are associated with genes related to DNA damage repair or autoimmune disease; others are linked to hormonal regulation.
"Our findings demonstrate the role of genes which regulate DNA repair and immune function, as well as genes affecting neuroendocrine pathways of ovarian function in regulating age at menopause, indicating the process of aging is involved in both somatic and germ line aging" the authors of the report wrote.
The findings "bring us closer to understanding the genetic basis for the timing of menopause. They may also provide clues to the genetic basis of early onset or premature menopause and reduced fertility,” said lead researcher Kathryn Lunetta, professor of biostatistics at the Boston University School of Public Health.
"We hope that as a better understanding of the biologic effects of these menopause-related variants are uncovered, we will gain new insights into the connections between menopause and cardiovascular disease, breast cancer, osteoporosis, and other traits related to aging, and that this will provide avenues for prevention and treatment of these conditions," she said.
Senior author Joanne Murabito, associate professor of medicine at the BU School of Medicine and director of the research clinic at the Framingham Heart Study, said further work is needed to determine what, if any, role the newly-discovered genes may play in other conditions associated with menopause.
"It will be important to determine if a genetic variant that directly influences age at menopause also increases risk for later life health conditions, such as breast cancer."
The authors of the report said they expected further research to identify "a substantial number of additional common variants" that impact age of menopause, and that many of them will be located in genes identified in their study.
The study examined more than 50,000 women of European descent who had experienced menopause between the ages of 40 and 60.
A separate, large-scale study of menopause onset in African-American women is also underway, which will help to determine whether the genetic variations that affect menopause onset in African-American women are similar to those of women of primarily European descent, the researchers said.
The current study was published online January 22 in the journal Nature Genetics.
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