Scientists have found 30 genes that control the timing of puberty in girls. Many of the newly identified genes also contribute to body weight and metabolism.
Genetic researchers from an international consortium called ReproGen, which includes Boston University School of Medicine (BUSM) and King’s College London’s Department of Twin Research, studied data on the genomes of 87,000 women throughout Europe, Australia and the U.S. to determine which genes seemed to unlock puberty. They also conducting replication studies in an additional 15,000 women.
They found 30 genes that were associated with onset of menarche — the first menstrual period — and among those, four had been previously associated with body mass index (BMI). Another three played a role in fat metabolism. (More on Time.com: Study: Signs of Early Puberty in More Young Girls)
The study suggests that some women may have a genetic predisposition toward early puberty and body weight. The authors say excess body fat may also trigger the puberty genes. Past studies have suggested that obesity could be a driver of early puberty, which is striking more and more American girls.
Early puberty could potentially increase girls’ lifetime risk of developing breast cancer — the body’s production of estrogen increases during sexual development, and longer exposure to estrogen is a risk factor for breast cancer. Childhood obesity also presents its own health risks, including higher odds of high blood pressure, high cholesterol and diabetes. (More on Time.com: Study: American Women Aren’t Sure What Overweight Looks Like)
“It is important to understand that these ‘genetic factors’ can be modified by changes in lifestyle. Efforts to reduce or prevent childhood obesity should in turn help reduce the early onset of puberty in girls,” senior author Dr. Joanne Murabito, an associate professor of medicine at BUSM and clinic director and investigator of the Framingham Heart Study, said in a statement.