Correlation of Gene Polymorphism of Manganese Superoxide Dismutase and Type 2 Diabetic Retinopathy

Objective To investigate the association of Val(16)Ala polymorphisms of manganese superoxide dismutase(Mn-SOD) gene and type 2 diabetic retinopathy(DR) in Chinese population. Methods Polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) was performed to determine Val(16)Ala polymorphism of Mn-SOD gene in 258 Chinese subjects,including 170 patients with type 2 diabetes mellitus(T2DM group) and 88 non-diabetic control subjects(control group).The T2DM was further divided into diabetic retinopathy group and non-diabetic retinopathy group\.The allele frequency and genotype distribution of Val(16)Ala polymorphism were compared in T2DM and the control group,and the association of Val(16)Ala polymorphisms of MnSOD gene with DR was also evaluated within T2DM group. Results The allele frequency and genotype of T2DM were not significantly different from those of the control group(P0.05).The frequency of VV genotype of Mn-SOD in the DR(+) was significantly higher than that in the DR(-) group(92.0% vs 77.1%,P0.01).Furthermore,logistic regression analysis showed that the Val(16)Ala polymorphisms was associated with DR independently(P=0.02,odds ratio=0.4785). Conclusion The Val(16)Ala polymorphism of Mn-SOD gene may not relate to type 2 diabetes,but it seems to be associated with DR in Chinese type 2 diabetic patients.