Superoxide Dismutase 1 (SOD1) gene +35A>C (intron3/exon3) Polymorphism in Diabetic Nephropathy patients among Bangladeshi Population


Laily Akter Akhy, Promita Deb, Manisha Das, Liaquat Ali, M. Omar Faruque, Zahid Hassan

Background and Aim: Superoxide dismutase 1 (SOD1) gene +35A>C (intron3/exon3) polymorphism (rs2234694) has been found to be associated with SOD1 enzyme activity modulation. SOD1 is known as free radical scavengers. Along with metabolic processes hyperglycemia also produces free radical particles. Therefore, SOD1 +35A/C polymorphism may interplays in the development of complications of diabetes. The present study has been aimed to investigate the association of this polymorphism in diabetic nephropathy (DN) subjects of Bangladeshi population. Subjects and Methods: 150 DN, 109 type2 diabetes mellitus (T2DM) subjects without nephropathy and 144 healthy control subjects were recruited in the study. Genomic DNA was extracted from whole blood using commercial kit. SOD1 gene +35A>C (intron3/exon3) polymorphism was investigated using polymerase chain reaction-restriction fragment length polymorphism method. Data were analyzed using Statistical Package for Social Science for windows version 17. Results: The SOD1 A>C genotype frequencies (AA for wild and AC for heterozygous variant [Ht]) were 0.972 and 0.028 for AA and AC in control subjects, 0.963 and 0.037 for T2DM and 0.907 and 0.093 for DN subjects, respectively. These genotype frequency distribution between the groups have shown significant association in c2 -test (χ2 =5.493; P = 0.019). Odds ratio (OR) of the genotypes between controls and DN have shown significant (OR/P = 3.603/0.027; confidence interval=1.157-11.220). Genotypes of Ht in DN are male preponderance. Conclusions: (a) +35A>C polymorphism in SOD1-gene possibly involve in the development of nephropathy in Bangladeshi Type 2 diabetic subjects; (b) Male DN subjects of Bangladeshi population are preponderant for +35A>C polymorphism in SOD1-gene.