Polymorphism of the serotonin 5-HT1B receptor gene (HTR1B) associated withminimum lifetime body mass index in women with bulimia nervosa

Background: Preclinical research has shown that the serotonin-1B receptor h as important modulatory effects on feeding behavior and thus body weight. I n the current study, we examined whether genetic variation of the serotonin -1B receptor was associated with minimum and maximum lifetime body mass ind ices (BMIs) in a sample of women with bulimia nervosa (BN). Methods: Ninety-eight women with BN were genotyped based on the G861C polym orphism of the serotonin-IB receptor gene (HTR1B). Minimum and maximum life time BMIs were compared across the three genotypic groups using analysis of variance. Results: There was a highly significant difference in minimum lifetime BMI across the three genotypic groups (p =.001). Both the GIC and CIC genotypes were associated with significantly lower minimum lifetime BMls than was th e GIG genotype. Maximum lifetime BMI was not significantly different across groups. These results were not attributable to different lifetime rates of anorexia nervosa across the three genotypic groups. Conclusions: These preliminary findings suggest a possible association bem, ,een HTR1B genetic polymorphism and minimum lifetime BMI in women with BN. These findings may shed light on why, in response to dieting, some BN patie nts achieve lower BMIs, whereas others have a natural limitation to their w eight loss. Pending replication in a larger sample, these findings Point to a possible genetic factor of fundamental importance to the BN population. (C) 2001 Society of Biological Psychiatry.