Eating disorders such as anorexia and bulimia have long been known to run in families, but scientists haven’t been able to identify specific gene mutations linked to them—until now. In a recent study published in the Journal of Clinical Investigation, researchers studied the genes of two families severely affected by eating disorders and found two mutations associated with the mental conditions.
“These mutations are rare, occurring in less than 1 percent of the population,” said study co-author Dr. Michael Lutter, assistant professor of psychiatry at the University of Iowa College of Medicine. But about 85 to 90 percent of the family members who carried one of these mutations wound up with either anorexia or bulimia, he added; that compares to a prevalence of 1 to 4 percent in the general population.
In the study, 20 members from three generations of one family (10 individuals with eating disorders and 10 unaffected), and eight members of a second family (six affected and two unaffected) were analyzed.
The two gene mutations interact with the same signaling pathway in the higher reasoning centers of the brain’s cerebral cortex. “These genes seemed to be turned on by calorie restrictions and exercise,” Lutter said, “and they enable the body to adapt to a low calorie state so people take in less and less food.”
While the findings need to be replicated, they might prove useful to find new treatments for eating disorders. Currently, no drugs have been approved to treat anorexia and certain antidepressants used to manage bulimia have only modest efficacy, Lutter said.