Genetic risk factors for diabetic retinopathy

Abstract

Although polymorphism of the angiotensin-converting enzyme (ACE) gene has been reported to be a possible risk factor for diabetic nephropathy, the association between diabetic retinopathy (DR) and genetic factors is still unclear. Therefore, a study of associations between DR and genes for ACE, angiotensinogen (AGN), and apolipoprotein E (ApoE) was conducted in 100 patients with type 2 diabetes of longer than 10 years' duration. The patients were placed in one of 4 groups: those without DR (nonDR), those with simple DR (SDR), those with preproliferative DR (prePDR), and those with proliferative DR (PDR). ACE and AGN gene polymorphisms were examined using DNA extracted from patient's leukocytes and ApoE phenotype was determined by isoelectrophoresis. Of the 3 genetic factors, ACE was the only one found to be significantly (p = 0.047, chi square) associated with the development of DR. DR was more severe in patients with the D allele of the ACE gene than in those without the D allele (p = 0.014, Kruskal-Wallis rank test). In contrast, there was no significant relationship between AGN, ApoE, and DR. In conclusion, ACE gene polymorphism can be a potent risk factor not only for diabetic nephropathy but also for diabetic retinopathy.