Metallothionein polymorphisms in a Northern Spanish population with neovascular and dry forms of age-related macular degeneration

<p><i>Background</i>: To elucidate the potential role of single nucleotide polymorphisms (SNPs) in the metallothionein (MT) genes in Northern Spanish patients with age-related macular degeneration (AMD).</p> <p><i>Methods</i>: A total of 130 unrelated Northern Spanish natives diagnosed with AMD (46 dry, 35 neovascular, and 49 mixed) and 96 healthy controls, matched by age and ethnicity, were enrolled in a case–control study. DNA was isolated from peripheral blood and genotyped for 14 SNPs located at 5 MT genes (<i>MT1A</i>: rs11076161, rs 11640851, rs8052394, and rs7196890; <i>MT1B</i>: rs8052334, rs964372, and rs7191779; <i>MT1M</i>: rs2270836 and rs9936741; <i>MT2A</i>: rs28366003, rs1610216, rs10636, and rs1580833; <i>MT3</i>: rs45570941) using TaqMan probes. The association study was performed using the HaploView 4.0 software.</p> <p><i>Results</i>: The allelic and genotypic frequencies analysis revealed that rs28366003 at <i>MT2A</i> gene is significantly associated with dry AMD. The frequency of genotype AG was significantly higher in dry AMD than in control cases (<i>p</i> = 2.65 × 10<sup>−4</sup>; AG vs. AA) conferring more than ninefold increased risk to dry AMD (OR = 9.39, 95% CI: 2.11–41.72), whereas the genotype AA confers disease protection (OR = 0.82, 95% CI: 0.71–0.95). No statistically significant differences were observed between AMD subjects and controls in the rest of the 14 SNPs analyzed.</p> <p><i>Conclusions</i>: The present study is the first to investigate the potential association of SNPs at MT genes with susceptibility to AMD. We found a significant association of SNP rs28366003 at <i>MT2A</i> gene with susceptibility to the dry form of AMD in a Northern Spanish population.</p>