The Timing of the Onset of Puberty in Girls May Affect Health Later in Life, Study Says

This is the first time that it’s been shown that imprinted genes can control the rate of development after birth.

Does timing matter when it comes to when girls get their first period? According to new research, the answer is yes. In fact, scientists believe that puberty timing in girls could be linked to important health conditions later in life.

An international study of more than 180,000 women, which involved scientists from 166 institutions worldwide, including Boston University School of Medicine, found that ‘imprinted’ genes, a small subset of genes whose activity differs depending on which parent passes on that gene, influences the age at which girls reach sexual maturity.

This is the first time that it has been shown that imprinted genes can control rate of development after birth. The finding was published Wednesday in the journal Nature.

According to the study:

The researchers identified 123 genetic variations that were associated with the timing of when girls experienced their first menstrual cycle by analysing the DNA of 182,416 women of European descent from 57 studies. Six of these variants were found to be clustered within imprinted regions of the genome.

The activity of imprinted genes differs depending on which parent the gene is inherited from – some genes are only active when inherited from the mother, others are only active when inherited from the father. Both types of imprinted genes were identified as determining puberty timing in girls, indicating a possible biological conflict between the parents over their child’s rate of development. Further evidence for the parental imbalance in inheritance patterns was obtained by analysing the association between these imprinted genes and timing of puberty in a study of over 35,000 women in Iceland, for whom detailed information on their family trees were available.

Joanne Murabito, the senior author of the study, who is also an associate professor of medicine at Boston University School of Medicine and at Framingham Heart Study says that the findings demonstrate a “complex network of genetic factors underlying the timing” of menarche (the first menstral cycle). “Menarche is associated with the development of health conditions later in life in women such as diabetes, cardiovascular disease, and breast cancer,” Murabito says. “By studying genetic factors, we hope to better understand how puberty timing in girls is linked to important health conditions in women.”