The research may help explain why patients from families with a history of early puberty are affected and identify other members at risk.
'These findings will open the door for a new understanding of what controls the timing of puberty', said Dr Ursula Kaiser, co-senior study author. 'It also will allow doctors to diagnose the cause of precocious puberty in a subset of patients, or to identify patients at risk for developing precocious puberty, especially if others in their family are affected'.
Central precocious puberty is where puberty begins before age eight in girls and age nine in boys. As well as having a negative impact on social and psychological development, this can lead to a higher risk of chronic diseases such as breast cancer, heart disease and diabetes.
The researchers performed whole-exome sequencing (the exome comprises all genes known to code for proteins) of 40 individuals from 15 families with central precocious puberty. In five of the families, they identified mutations in the MKRN3 gene which is linked to the activation of pubertal hormones.
These mutations disrupt the function of one of the proteins that triggers puberty, makorin RING-finger protein 3. The MKRN3 gene is paternally expressed, which means that only the copy of the gene inherited from the father is used in making proteins.
Although early puberty is likely to involve both genetic and environmental factors, the timing of its onset is not well understood. 'By better understanding the role of this gene in the timing of puberty, we may be able to gain insights into how other factors, such as environmental factors, may influence pubertal timing', said Dr Kaiser.
'Although the finding of a genetic cause for central precocious puberty is a significant contribution to further understanding human puberty, an explanation of why puberty starts at about the time of the junction of the first and second decades of human life has yet to be had', Professor Ieuan Hughes commented in a New England Journal of Medicine editorial.