Association of Genes on Chromosome 6, GRIK2, TMEM217 and TMEM63B (Linked to MRPL14) with Diabetic Retinopathy

<b><i>Purpose:</i></b> Diabetic retinopathy (DR) is one of the most common complications of diabetes mellitus (DM). The susceptibility genes responsible for increasing the risk for DR in type 2 diabetes (T2D) were sought in this study. <b><i>Methods:</i></b> A case-control study was carried out, comprising 749 unrelated T2D individuals with (n = 174) and without (n = 575) DR. Genotypic distributions of single nucleotide polymorphisms (SNPs) were determined for subjects with and without DR. <b><i>Results:</i></b> Eight chromosome 6 SNPs, having the most significant differences, were delineated: <i>rs10499298, rs10499299, rs17827966, rs1224329, rs1150790, rs713050, rs2518344</i> and <i>rs487083;</i> all were associated with genes <i>TMEM217, MRPL14</i> and <i>GRIK2.</i> After adjusting for the duration of DM and levels of hemoglobin A_1c, the TT genotype of <i>rs713050</i>, and the AG + AA genotypes of <i>rs2518344</i> and <i>rs10499298,</i> differed significantly between those with and without DR. Haplotype analysis revealed haplotype C-A-C, residing in <i>rs10499299, rs10499298</i> and <i>rs17827966,</i> to have significant linkage disequilibrium. <b><i>Conclusions:</i></b> We identified new loci on chromosome 6 associated to DR; all loci showed high levels of linkage disequilibrium.