Papel de polimorfismos en genes serotonérgicos y dopaminérgicos en los trastornos de la conducta alimentaria

Abstract

In the past 30 years, researchers have identified a number of neurotransmitters, hormones and peptides with the ability to regulate eating behavior and/or psychopathological characteristics that are often observed in patients with eating disorders (ED). Among the studied neurotransmitters, serotonin has traditionally been attracted most of the attention, as it is known its importance in feeding, mood and social behavior. However, dopamine neuronal functions also indicate that this neurotransmitter may play a role in ED. Thus, dopamine is involved in the regulation of feeding behavior, motor activity, distortion of body image and, especially, in reward processes. The aim of this study was to establish whether the existence of genetic polymorphisms in genes along serotonergic or dopaminergic pathways may influence the risk of developing an ED and/or modify physiological and psychopathological parameters in these patients. We analyzed 10 polymorphisms in genes encoding transporters (SLC6A4, DAT1) metabolizing enzymes (COMT) or receptors (5HT2A, DRD2, DRD3 and DRD4) of these catecholamines in 169 ED patients (105 with anorexia nervosa, AN, and 64 with bulimia nervosa, BN) and 240 healthy controls. Our results show an association between the 5HT2A A-1438G polymorphism and the risk of developing restrictive AN, as well as a moderate increase in the risk of BN in carriers of the DAT1 10R/9R polymorphism. Moreover, polymorphisms C-616G C-521T in the D4 dopamine receptor were associated with higher weights and body mass index in patients with bulimic behaviors. The analysis of the psychopathological characteristics of patients allowed us to identify two polymorphisms, 5HT2A A-1438G and DAT1 10R/9R as those genetic alterations with the greatest impact. Certain haplotypes were also identified in the D4 receptor gene which correlated with the scores measured by the psychological tests. Our results suggest that certain genetic variants in serotonergic and dopaminergic genes may have a major influence on the course of ED.