Association of HTR2A T102C and A-1438G polymorphisms with susceptibility to major depressive disorder: a meta-analysis.

Serotonin 2A receptor (HTR2A) gene was implicated to be associated with major depressive disorder (MDD) susceptibility due to its role of key neurotransmitter in many physiologic processes. A great number of related studies reported in different populations have emerged. The results of these studies, however, have been inconsistent and thereby definite conclusions are difficult to establish. With the cumulative data in recent years, it was necessary to carry out a comprehensive analysis of previous findings. Electronic databases were systematically searched for studies published before May 2013. Pooled odds ratios (OR) and 95 % confidence interval (CI) were estimated under three different genetic models. Subgroup and sensitivity analyses were also performed. A total of 21 studies, 3,299 patients and 4,092 controls, met the selection criteria. 15 studies included HTR2A T102C polymorphism (with a total of 2,409 patients and 3,130 controls), and 9 studies included HTR2A A-1438G polymorphism (with a total of 1,510 patients and 2,281 controls). Our results showed that no significant association of MDD susceptibility with T102C polymorphism was found in allelic analysis and genotypic analysis (For T vs. C: OR = 1.06, 95 % CI = 0.95-1.18, P = 0.307; For TT + TC vs. CC: OR = 1.07, 95 % CI = 0.90-1.28, P = 0.451; For TT vs. TC + CC: OR = 1.08, 95 % CI = 0.95-1.22, P = 0.235). With respect to A-1438G polymorphism, however, carriers with A allele tend to suffer from MDD (AA + AG vs. GG: OR = 1.20, 95 % CI = 1.02-1.43, P = 0.030). When stratified by race for T102C polymorphism and A-1438G polymorphism of the HTR2A, we found no significant association. In conclusions, our study suggests that the A allele of A-1438G polymorphism might play a role in susceptibility to MDD. On the contrary, T102C polymorphism does not seem to be capable of modifying MDD risk.