Supplementary Material for: Association between Polymorphisms of the DRD2 and ANKK1 Genes and Suicide Attempt: A Preliminary Case-Control Study in a Mexican Population

<b><i>Background:</i></b> The aim of this study was to analyze the possible association of polymorphic variants of the <i>DRD2</i> and <i>ANKK1</i> genes with suicide attempt in a Mexican population. <b><i>Methods:</i></b> We conducted a case-control study in 289 subjects (166 suicide attempters and 123 healthy controls). We genotyped 2 polymorphisms of <i>DRD2</i> (rs6275 and rs1799978) and 1 polymorphism of <i>ANKK1</i> (rs1800497); then we analyzed the association between suicide attempt and these polymorphisms through genotypes, alleles, and inheritance models. <b><i>Results:</i></b> Individuals who carried the TT genotype of the rs1800497 showed a 3-fold risk of attempting suicide (OR = 3.01; 95% CI 1.56–5.81, <i>p</i> = 0.001) when evaluated through the recessive model. In an analysis stratified by gender, this risk factor remained present among females (OR = 2.81; 95% CI 1.37–5.75) as well as males (OR = 3.3; 95% CI 1.01–10.77). <b><i>Conclusion:</i></b> Our results suggest that the rs1800497 variant of the <i>ANKK1</i> gene could increase the risk of suicide attempt in a Mexican population. However, further studies using larger samples are necessary to obtain more conclusive results.