Meta-analysis of association between TPH2 single nucleotide poiymorphism and depression.

• We included a large number of studies with Chinese participants. • Forty randomized controlled trials were pooled in a meta-analysis. • rs4570625 (T allele, T/T genotype) and rs17110747 (A allele) may be significant protective factors against depression. • rs120074175 (A allele, A/A genotype), and rs4290270 (T allele) may be significant risk factors for depression. • rs11178997 (A/A genotype) may be a significant risk factor for Chinese subjects. Tryptophan hydroxylase 2 (TPH2) plays a crucial role in the human brain. Although the association between the TPH2 gene and depression has been suggested in previous meta-analyses, studies based on Chinese subjects are often neglected. Therefore, we included some previous studies based on Chinese subjects to explore the relationship between TPH2 polymorphisms and depression via conducting an extensive meta-analysis. We reviewed 40 research papers that included data on TPH2 gene single nucleotide polymorphisms (SNPs) from 5766 patients with depression and 5988 healthy subjects. The analysis showed an association between polymorphisms in the TPH2 gene and depression, and some results were significant in 24 studies that included Chinese Han study participants. The results of our meta-analysis showed that rs4570625, rs17110747, rs120074175, rs4290270, rs120074175, and rs4290270 may be significantly associated with depression, and that rs11178997 (A/A genotype) may be a significant risk factor for depression in the Chinese subjects. Based on the results of this study, biological experiments should be performed in the future to explore how different SNPs affect depression. [ABSTRACT FROM AUTHOR]