We are increasingly aware of the genetic basis of AN but know far less about the genetics involved in binge eating. By analyzing the genome of tens of thousands of people living in Great Britain, a team headed by Drs. Christopher Hὓbel and Nadia Micali and their colleagues at the University of Geneva, and three other colleges have now described similarities and differences between the genetic bases of AN, BN, and BED and other psychiatric disorders.
The researchers also used health data and replies to health questionnaires from more than 20,000 volunteers, all taken from the UK Biobank. With this information, the team calculated more than 250 polygenic scores for each person. (Each polygenic score adds the risk of genes involved in a specific trait, such as depression.)
Significant associations were tested for replication in the Avon Longitudinal Study of Parents and Children (up to 217 cases and 3,018 controls). The researchers found that eating disorders differ in their genetic association with anthropomorphologic traits, such as weight, waist circumference, and body mass index (Int J Eat Disord. 2021.54:785).
Overall, the study results show that while there are strong genetic similarities between AN, BN, and BED, there are also striking differences. One major difference concerns the associated genetics of body weight regulation, which are opposite between AN on one side and BN and BED on the other. The latter are linked to a high genetic risk of obesity and a high BMI, according to the researchers. They added that the study results also support a clear genetic relationship between BED and attention deficit disorder, which has been noted clinically in the past.