Researchers find gene for precocious puberty

Researchers have identified the genetic mutation responsible for central precocious puberty. Experts say the finding may help unlock the mysteries surrounding the timing of puberty and make it possible to identify those at risk of early onset.

Investigators from Massachusetts, Brazil, and Belgium worked together to determine that mutations in a gene known as MKRN3 result in early activation of the central reproductive axis.

The MKRN3 gene is responsible for coding a protein called makorin ring finger protein 3. Mutations in the gene result in shortened MKRN3 proteins. The shortened proteins function improperly and can prematurely activate reproductive hormones and initiate early puberty.

Studying 40 people with central precocious puberty from 15 families, the researchers determined that all the affected individuals inherited the mutations from their fathers. Furthermore, they discovered that the MKRN3 gene is located on the same chromosome as the genes for Prader-Willi syndrome, a rare condition characterized by short stature, poor muscle tone, incomplete sexual development, cognitive disabilities, insatiable appetite, and severe obesity, but experts do not think that MKRN3 contributes to the condition.

The researchers admit that the function of the gene is not well understood and that the exact mechanisms by which mutations in the gene result in central precocious puberty are still a mystery, but they believe that their data are sufficiently compelling and statistically strong to indicate a causative role.

Central precocious puberty is generally defined as the development of secondary sexual characteristics before age 8 years in girls and before age 9 years in boys. Unlocking the mystery behind early puberty is important because it is associated with higher risks for certain diseases. For example, earlier age at menarche in girls is associated with increased risks of breast cancer, endometrial cancer, obesity, type 2 diabetes, and cardiovascular disease. In addition, central precocious puberty is associated with an increased incidence of conduct and behavioral problems during adolescence.