Polymorphisms rs6313 and rs6314 in Serotonin Receptor Gene (HTR2A) and Serotonin Concentration in Autistic Children

Abstract

Objective Genetic polymorphisms and mutations in candidate genes are considered important in the etiology of autism, and particular interest is focussed on the serotonin system. Here, we used SNP analysis in the serotonin receptor gene to identify differences between autistic and healthy control children. Methods Genetic association of rs6313 (T102C) and rs6314 (C1354T) polymorphisms in HTR2A gene with susceptibility to the development of autism in children were investigated using PCR-RFLP, and correlated serotonin levels in blood serum using ELISA method. Results We uniquely found an association between the presence of the T allele at the position rs6313 (OR=2.00, 95%CI: 1.23-3.26, p=0.005), and between the presence of the C allele at the position rs6314 (OR=2.24, 95% CI: 1.47-3.42, p=0.0002) of the serotonin receptor gene under conditions of a decreased ASD incidence. We also noted that T allele at the position rs6313, and C allele at the position rs6314 was 3 times more frequent in Control males than in ASD males. We found no statistical significant correlation between HTR2A SNPs and the blood serum level of serotonin between autistic and control children. Conclusion This study shows the involvement of HTR2A, rather than the concentration of serotonin, in the development of autism, and provides a rationale for future design of therapeutic modalities based on the serotonin system for childhood autism.