Original Data

Rev Diabet Stud, 2005, 2(2):70-74 DOI 10.1900/RDS.2005.2.70

Manganese Superoxide Dismutase Alanine to Valine Polymorphism and Risk of Neuropathy and Nephropathy in Egyptian Type 1 Diabetic Patients

Tarek M. El Masry1, Mona A. M. Abou Zahra1, Mohammed M. El Tawil2, Rawhia A. Khalifa3

1Department of Clinical Pathology, Ain Shams University Hospital, Cairo, Egypt.
2Department of Pediatrics, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
3Department of Clinical Pathology, Research Institute of Ophthalmology.
Address correspondence to: Tarek M. El Masry, e-mail: tarek_msry@yahoo.com.

Keywords: antioxidants, type 1 diabetes, microangiopathy, SOD2 gene, neuropathy


Oxidative stress, characterized by a marked increase in the level of oxygen free radicals (OFR), has been implicated in the development of diabetic microangiopathic complications, such as diabetic neuropathy (DN) and nephropathy (DP). Antioxidant enzymes may protect against the rapid onset and progression of microangiopathy, by reducing the excess of OFR and peroxides. Mutations and polymorphisms in genes encoding such enzymes may therefore result in a predisposition to this disorder. AIM: we investigated the role of genes encoding the antioxidant enzyme, mitochondrial superoxide dismutase (Mn-SOD2), in DN and DP pathogenesis in an Egyptian population. We studied Ala(-9)Val polymorphism of the Mn-SOD2 gene in type 1 diabetic patients (n = 65) with DN (n = 40) or DP (n = 45). METHODS: we used polymerase chain reaction (PCR) assays with restriction fragment length polymorphism for rapid detection of polymorphisms. These assays involved the use of mismatch PCR primers to create restriction sites in the amplified product only in presence of the polymorphic base. The PCR product was then digested with AgeI restriction enzyme to detect Ala(-9)Val polymorphic sites. RESULTS: the frequencies of the Ala allele (odds ratio (OR) = 0.438, 95% CI of 0.247 - 0.778) and the Ala/Ala genotype (OR = 0.26, 95% CI of 1.39 - 10.266) were significantly lower in diabetic neuropathy patients. In contrast, the frequencies of the Val allele (OR = 2.282, 95% CI of 1.286 - 4.05) and the homozygous Val/Val genotype (OR = 6.68, 95% CI of 0.3 - 0.76) were significantly higher in patients with DN than diabetics without neuropathy. Although the Val allele was more frequently detected in DP patients than diabetics without nephropathy (OR = 3.2), this difference was statistically non-significant. In conclusion, Ala(-9)Val substitution in the Mn-SOD2 gene was associated with DN in Egyptian diabetic children but not a significant factor in diabetic patients with nephropathy.

Fulltext: HTML , PDF (581KB)

This article has been cited by other articles:

Association of the C47T polymorphism in SOD2 with diabetes mellitus and diabetic microvascular complications: a meta-analysis

Tian C, Fang S, Du X, Jia C

Diabetologia 2011. 54(4):803-811

The sequence polymorphism of MnSOD gene in subjects with respiratory insufficiency in COPD

Pietras T, Szemraj J, Witusik A, Holub M, Panek M, Wujcik R, Gorski P

Med Sci Monit 2010. 16(9):CR427-CR432

Association between the rs4880 superoxide dismutase 2 (C>T) gene variant and coronary heart disease in diabetes mellitus

Jones DA, Prior SL, Tang TS, Bain SC, Hurel SJ, Humphries SE, Stephens JW

Diabetes Res Clin Pract 2010. 90(2):196-201

Association between SOD2 T-9C and MTHFR C677T polymorphisms and longevity: a study in Jordanian population

Khabour OF, Abdelhalim ES, Abu-Wardeh A

BMC Geriatr 2009. 9:57

Age-dependent dichotomous effect of superoxide dismutase Ala16Val polymorphism on oxidized LDL levels

Dedoussis GV, Kanoni S, Panagiotakos DB, Louizou E, Grigoriou E, Chrysohoou C, Pitsavos C, Stefanadis C

Exp Mol Med 2008. 40(1):27-34