Dozens of Genetic Markers Contribute to Obesity

Mar 23, 2015

Inside the Human Genomics Lab at Pennington Biomedical Research Center, Dr. Tuomo Rankinen points to a chip -- much like one you'd find in a computer -- that contains DNA samples. The chips are designed to read genetic markers, or DNA sequences, that determine things like blood type and eye color, and also risk for diseases like obesity. 

Researchers have known for nearly a century that our genes affect our weight. But what they didn't know was which genes were responsible, or how many.  As a result of global collaboration, researchers now know 97 genetic markers that play a role in weight, 60 of which were previously undiscovered.

Initial analysis indicates that these genetic markers might be working in the brain, something researchers were not expecting.  They still don't know the exact function of the markers, but Dr. Rankinen says it's possible that they are working in the brain, regulating pathways that affect energy expenditure, satiety, or food intake.

What they do know for certain is that the genetics of obesity is much more complex than previously thought.  Dr. Mark Sarzynski is an Assistant Professor in the Human Genomics Lab at Pennington. 

"Even these hundred markers may not be the end all, be all," Dr. Sarzynski explains.

It's a welcomed complexity, because the more genetic markers are known, the more ways might be developed to attack the obesity problem.

One of the ultimate goals of this research is the movement toward personalized interventions.

"Maybe certain people with a certain genetic profile will respond better to a diet that's low carb versus high fat," says Dr. Sarzynski.  Which means people could avoid the frustration of trying different treatments, and know sooner which one they'll respond to best.

Until then, Doctors Rankinen and Sarzynski will investigate exactly what those 97 genetic markers do and how many more might be contributing to weight problems.