Genes can indirectly influence the age at which girls have their first period by accelerating weight gain in childhood, a known risk factor for early puberty, a Cambridge-led study has found. Other genes can directly affect age of puberty, some with profound effects. In the largest study of its kind to date, an international team led by researchers at the Medical Research Council (MRC) Epidemiology Unit, University of Cambridge, studied the DNA of around 800,000 women from Europe, North America, China, Japan, and Korea.
Published today in Nature Genetics , the researchers found more than 1,000 variants – small changes in DNA – that influence the age of first menstrual period. Around 600 of these variants were observed for the first time. The age at which girls hit puberty and start having periods normally occurs between ages 10 to 15, though this has been getting earlier and earlier in recent decades.
The reasons for this are not fully understood. Early puberty is linked with increased risk of a number of diseases in later life, including type 2 diabetes, cardiovascular disease, and certain cancers. Later puberty on the other hand, has been linked to improved health in adulthood and a longer lifespan.
Just under half (45%) of the discovered genetic variants affected puberty indirectly, by increasing weight gain in early childhood. Many of the genes we've found influence early puberty by first accelerating weight gain in infants and young children. This can then lead to po.
