Supplementary Material for: Genetic Variants in ICAM1, PPARGC1A and MTHFR Are Potentially Associated with Different Phenotypes of Diabetic Retinopathy

<b><i>Purpose:</i></b> To explore phenotype-genotype correlations that may contribute to a better understanding of diabetic retinopathy (DR). <b><i>Procedures:</i></b> An exploratory association study was performed to identify genetic variants associated with non-proliferative DR (NPDR) in 307 type 2 diabetic patients who were previously stratified into 3 different phenotypes of NPDR progression. The 307 patients were genotyped for 174 single nucleotide polymorphisms of 11 candidate genes <i>(ACE, AGER, AKR1B1, ICAM1, MTHFR, NOS1, NOS3, PPARGC1A, TGFB1, TNF</i> and <i>VEGFA)</i>. <b><i>Results:</i></b> Significant associations were observed for <i>PPARGC1A</i> rs16874120 with phenotype A (odds ratio, OR = 0.60, 95% confidence interval, CI 0.36-0.99), <i>ICAM1</i> rs1801714 with phenotype B (OR = 3.32, 95% CI 1.05-10.50) and both <i>PPARGC1A</i> rs10213440 (OR = 2.00, 95% CI 1.07-3.73) and <i>MTHFR</i> rs1801133 (OR = 1.84, 95% CI 1.08-3.11) with phenotype C. <b><i>Conclusions:</i></b> Results indicate that specific gene variants in <i>ICAM1</i>, <i>PPARGC1A</i> and <i>MTHFR</i> are associated with different NPDR phenotypes, being likely candidates to explain different disease mechanisms underlying the different phenotypes. This is the first study to show correlations between specific gene variants and NPDR phenotypes, opening new perspectives on DR.