Researchers find genes associated with onset of puberty

 
June 08, 2009
The genes that may cause a normal variation in the timing of female sexual maturation have been identified, according to a researcher at the University of North Carolina’s Gillings School of Global Public Health and 38 other researchers from around the world. Their findings, published in the June issue of Nature Genetics, also indicate a genetic association between age at first menstruation, height and possibly body mass index (BMI).

Dr. Nora Franceschini

Dr. Nora Franceschini

Nora Franceschini, MD, MPH, research assistant professor of epidemiology at UNC, is one of the leading authors of the study, which analyzed data from more than 17,000 Caucasian women participating in eight different studies. The researchers found the first evidence of a correlation between puberty and genes in chromosomes 6 and 9. Age of first menstruation, which occurs at a mean age of 13 years in Caucasian (or white) girls, was used as a proxy for puberty, which generally occurs two years earlier.

“Studies already published show that the same gene in chromosome 6 also accounts for height,” Franceschini says, explaining the significance of finding the gene. “In general, the earlier the menarche, the shorter the girl.” Growing plates in the femur (thigh bone) and other bones are closed when girls begin menstruation, she adds.

According to the paper, titled “Meta-analysis of genome-wide association data identifies two loci influencing age at menarche,” previous studies also have shown that “girls with earlier age at menarche tend to have greater body mass index (BMI) and body fat than girls with a later age at menarche.” The authors further suggest that the genes influencing age at first menstruation may also point to regulatory mechanisms involved in normal growth and obesity.

“Our findings could trigger new research about human growth factors and diseases associated with menorrhea,” Franceschini says. “There is also some evidence that the age of menarche is associated with breast cancer and stroke.” She says the genes found to influence puberty in girls seem to be relevant to boys, too, but their study was not extended to boys.

Franceschini received a medical degree from the Universidade Federal do Rio Grande do Sul in Brazil before receiving clinical training in medicine at the University of Utah and in nephrology at Duke University. She earned a Master of Public Health in epidemiology from UNC and continued postdoctoral training in genetic epidemiology with Kari North, PhD, and Gerardo Heiss, MD, PhD, from the cardiovascular disease research group in the Department of Epidemiology.

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Read the paper at http://www.nature.com/ng/journal/v41/n6/pdf/ng.386.pdf.

Contact Nora Franceschini at noraf@unc.edu.

UNC Gillings School of Global Public Health contact: Ramona DuBose, director of communications, at (919) 966-7467 or ramona_dubose@unc.edu.