Association Study Between the Triallelic Polymorphism of SLC6A4 Gene and Eating Disorders

Abstract

The serotonin transporter is encoded by the SLC6A4 gene and has been an interesting candidate for anorexia nervosa (AN) and bulimia nervosa (BN). The present study analyzed the association between the triallelic model of the SLC6A4 gene and eating disorders in Mexican population. Materials and Methods: The 5-HTTLPR/rs25531 polymorphism was analyzed in 458 eating disorder patients and 337 control subjects. Genotype and allele analyses were examined in 206 BN and 79 AN patients and compared with the control group. Furthermore, genotype and allele analyses were performed on AN-Spectrum (AN-R, AN-BP and AN-EDNOS) and BN-Spectrum (BN-P, BN-NP and BN-EDNOS) groups and compared with the control group. Results: Case-control analysis showed that BN patients had an increased frequency of the S/LG alleles compared to controls (c2=6.9, df=1, p=0.0088). However, no association was found between AN and the 5-HTTLPR/rs25531 polymorphism (c2=3.3, df=1, p=0.0654). Also, an association was observed in genotype distribution when comparing AN-spectrum and control groups (c2=10.1, df=2, p=0.0069); however, analysis of allele frequencies did not show differences after Bonferroni correction (c2=5.6, df=1, p=0.0177). Finally, analysis of BN-Spectrum showed a high frequency of S/LG alleles compared to control group (c2=7.3, df=1, p=0.007). Conclusion: The low activity alleles of the 5- HTTLPR/rs25531 polymorphism of the SLC6A4 gene may play a significant role in the etiology of BN subtypes in Mexican population.