Objective: The aim of this study was to examine the association between polymorphisms (SNP) in the tryptophan hydroxylase-2 (TPH2) gene and late-onset depression (LOD) in the Brazilian population.
Methods: We genotyped 8 tag SNPs in the TPH2 gene in 84 outpatients with LOD and 79 individuals belonging to the comparison group to investigate an association between the TPH2 gene and LOD.
Results: Our findings suggested an association between tag SNP rs4565946 heterozygous C/T (p = 0.034; χ2 = 6.7; df = 2) and decreased risk of LOD. The tag SNP rs11179000 ancestral homozygous A/A (p = 0.025; χ2 = 7.3; df = 2) and increase risk of LOD and allelic association of ancestral allele A and increase risk of LOD was demonstrated (p = 0.005; χ2 = 7.8; df = 1).
Conclusion: We found the statistically significant association between two tag SNPs and LOD. Our results support the hypothesis that the TPH2 gene is associated with LOD.