Indications of pubertal timing found through epigenetics

MONTREAL — Clues into the timing of puberty are being increasingly revealed through the exploration of epigenetics, according to research presented here at the annual meeting of the Canadian Pediatric Endocrine Group.

Sergio Ojeda, DVM, a senior scientist in the Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, told Endocrine Today that epigenetics, “epi” meaning above, affects the activity of the genes without modifying the DNA sequence of the genes.

“It is important that clinicians be aware that the initiation of puberty not only depends on genetic factors, but also on epigenetic clues,” said Ojeda, who is undertaking a study with Canadian investigators to explore the role of a gene known as LIN28 in the early onset of puberty and age of first menarche.

Variations in the DNA sequence of LIN28 have been found to be associated with early puberty.

“Epigenetic mechanisms are activated by environmental inputs,” Ojeda said. “Nutrition is a good example. Nutrition affects the structure of chromatin — the combination of DNA and proteins that regulates gene activity. Changes in chromatin structure are epigenetic modifications that may be critical for the timing of puberty.”

One of the recent revelations from Ojeda and colleagues is that puberty is held in check by gene silencing and is ultimately initiated when this inhibition is lifted and stimulatory mechanisms come into play.

There has been a progressive advancement of puberty in the past 2 decades such that girls as young as age 7 years are showing signs of puberty, Ojeda said, adding that this early onset of puberty may be explained in part by epigenetic mechanisms.

Studies show correlations between the early onset of puberty in females and the development of breast and uterine cancers later in life, making advancing puberty a worrisome phenomenon, Ojeda said.

Children should minimize the ingestion of food with high fat and high caloric content. The intake of food ingredients containing estrogen-like compounds, such as soy, and additives present in processed foods should also be minimized to reduce the chance of an early initiation of puberty, according to Ojeda.

The timing of puberty is influenced by the genetic makeup of an individual. In general, black girls experience puberty earlier than Hispanic and white girls, who, in turn, experience puberty before Asian girls, Ojeda said. – by Louise Gagnon

For more information:

Palmert M. Beyond sequence variation: Emerging evidence that epigenetics is an important regulator of pubertal timing. Presented at: Canadian Pediatric Endocrine Group 2014 Scientific Meeting; Feb. 20-22, 2014; Montreal.

Disclosure: Ojeda reports no relevant financial disclosures.