Study: How Environment Affects Onset of Puberty

A new Danish study revealed a possible epigenetic link between the environment and the onset of puberty in boys and girls.

The study, published in the journal Scientific Reports, suggest that chemical modification in the human genome, or known as epigenetic modifications, could be used to determine the onset of puberty on children.

"To our knowledge, this study is the first to demonstrate how the environment can affect the pubertal onset in humans. It gives us a significant insight in to the crucial role of epigenetic factors on our reproductive development," said Professor Anders Juul, senior author of the study, in a statement.

For the study, researchers enrolled 32 boys and 22 girls from the COPENHAGEN Puberty Study. Female participant underwent pubertal staging of breast development according to Tanner's classification evaluated by palpation, while male participants have their testicular volume measured using orchidometry. A breast Tanner stage of two or above and a testicular volume of 4 mL or more were considered to be markers of pubertal onset in girls and boys, respectively.

The researchers then focused on the role of epigenetic in pubertal timing and have discovered several areas of human genome that is being controlled epigenetically during puberty.

 After analyzing the longitudinal genome-wide changes in DNA methylation in peripheral blood samples of all the children, the researchers noted a tight link between changes in single methylation sites, physiological pubertal transition and altered reproductive hormone levels.

"Changes in the DNA methylation patterns can be caused by many different factors. However, we could see very specific changes when children went through puberty, and have subsequently shown that this also leads to changes in the expression of the methylated genes," explained Kristian Almstrup, Senior epigenetic researchers and lead author of the study, in a press release.

In conclusion, researchers suggests that specific changes in the methylation of a child's DNA could determine whether the child has entered puberty or not, making it a potential predictor of child's pubertal stage.