Possible association of CAT gene-21A/T on diabetic retinopathy in Sudan

Abstract

Abstract Background: Catalase (CAT) is one of the active anti-oxidative enzymes that its deficiency has been related to diabetic retinopathy. The aim of the current study was to determine whether CAT-21 A/T polymorphism is associated with the development of diabetic retinopathy or not among Sudanese patients with type 2 diabetes mellitus. Methods: A case-control study was conducted at Makkah Eye Complex, Khartoum, Sudan. Fifty patients with diabetic retinopathy (cases) and 50 diabetic control were included in this study. The single nucleotide polymorphism (SNP) in the promoter region of CAT gene -21A/T was genotyped using polymerase chain reaction and restriction fragment length polymorphism endonuclease Hinf1 enzyme (PCR-RFLP) in cases and control. Results: The TT genotype frequency of the CAT-21A/T was significantly higher in cases compared with control (P=0.043), and showed that a risk effect in diabetic retinopathy patients (OR=2.56, 95% CI=1.01-6.45). While the AA genotype showed a protective consequence (P= 0.011, OR=0.33, 95% CI= 0.13-0.79) in control. The allele frequency of the variant T allele was significantly different in the cases group (P=0.003, OR=2.35, 95% CI=1.33– 4.16). Conclusion The TT genotype and T allele frequency of CAT-21A/T polymorphism may be associated with an increased risk of diabetic retinopathy in this setting.