265 Lack of association between -308g/a polymorphism of tumor necrosis factor - α gene and myocardial infarction in Tunisian population

Abstract

Tumor necrosis factor alpha (TNF-α) is a primary pro-inflammatory cytokine expressed in adipocytes and plays a crucial role in the inflammatory process, it also stimulates the production of chemo-attractant cytokines which may be a key feature of atherosclerosis. Relationship between polymorphisms in TNF-α gene and coronary heart disease has been reported, but remains a controversial subject. The aim of our study was to investigate the possible association between the -308 G/A promoter variant in the TNF-α gene and myocardial infarction (MI) in a sample of Tunisian population. Our study included 299 male patients MI enrolled from the department of Cardiology at Rabta University Hospital of Tunis and 408 male volunteer subjects with no history of MI. Genomic DNA was extracted from white blood cells, amplified by PCR followed by a digestion with the appropriate restriction endonuclease ( NcoI ) and genotyped by electrophoresis in agarose gels. Statistical analyses were performed using SPSS 11.5. MI patients compared to controls had significantly higher prevalence of diabetes, hypertension, cigarette smoking and dyslipidemia (p <0.001). The genotype frequencies were in agreement with those predicted by the Hardy-Weinberg equilibrium in MI (X 2 =0.137, p=0.934) and control groups (X 2 =0.10, p=0.951). In MI patients the genotype frequencies were 63% for GG, 34.6% for GA and 2.5% for AA, and were 62.2% for GG, 34.8% for GA and 3.0% for AA in controls. No significant difference in genotype and allele frequencies of the TNF - α –308G/A polymorphism were detected between MI and control subjects. In both groups, analyses of variance of lipid levels across –308G/A genotypes showed no significant difference. Our findings revealed that the -308G/A polymorphism of TNF-α gene is not a relevant marker of MI in the Tunisian population.