An international team of scientists, including six from Vanderbilt University, has identified the first unique genetic determinants of body mass index (BMI) in people of African ancestry.
The discovery, published on Sunday in Nature Genetics to coincide with the 10th anniversary of the completion of the Human Genome Project, eventually could lead to new ways to treat or prevent obesity in this high-risk population.
Genetic variations associated with BMI have previously been identified through genome-wide association studies (GWAS) — examinations of genetic information — conducted in large groups of individuals of European and Asian descent.
But until now, this hadn’t been done in people of African ancestry.
In the current study, called a meta-analysis, the researchers pooled data from 36 GWAS involving more than 39,000 men and women of African ancestry.
Most of the previously discovered genetic variants influencing BMI also were found in this study.
But the researchers discovered two and possibly three new areas in the genome that are uniquely associated with BMI in people of African ancestry.
“This phenomenon could explain some of the observed disparities in obesity risk between these populations,” said Todd Edwards, Ph.D., assistant professor of Medicine.
Edwards, an investigator in the Vanderbilt Center for Human Genetics Research and the Vanderbilt Epidemiology Center, is pursuing this study with his colleague and wife, Digna Velez Edwards, Ph.D., who also contributed to the paper published this week.
Without the completion of the Human Genome Project, an international, 13-year-long quest that ultimately mapped the complete set of DNA in the human body, “this work would be impossible,” Edwards said.
“The HGP provided the basis for discovering genetic variation in continental populations of humans,” he said.
“This inter-individual variability is what we evaluate when we conduct studies to discover the determinants of complex traits such as BMI.”
Other Vanderbilt faculty members who contributed to the study were Melinda Aldrich, Ph.D., MPH, William Blot, Ph.D., Edmond Kabagambe, Ph.D., and Wei Zheng, M.D., Ph.D., MPH.
Vanderbilt’s participation in the study was supported in part by National Institutes of Health grants CA068485 and CA092447.
