The -148 c>t fibrinogen promoter polymorphism and myocardial infarction in the Maltese population

Abstract

Fibrinogen is a soluble glycoprotein with a molecular weight of 340kDa synthesized mainly in the liver that acts both as a clotting factor and an acute phase reactant. Several studies have shown that plasma fibrinogen levels are affected by environmental and demographic factors including gender, advancing age and seasonality. Intrinsic factors, polymorphisms, within the fibrinogen gene, FGA, FGB and FGG which encode for the Aα, Bβ and γ chains respectively of the fibrinogen molecule were also found to affect plasma fibrinogen levels. Since the β-chain synthesis is the limiting step in the production of mature fibrinogen, it has been more extensively studied. Several studies have shown an association between the β-chain fibrinogen polymorphisms and plasma fibrinogen levels. However, there are still conflicting results on whether or not individual SNPs confer increased risk of Myocardial Infarction. In this study, samples from the Maltese Acute Myocardial Infarction (MAMI) collection were tested for the -148C>T SNP (rs1800787) using Polymerase Chain Reaction, Restriction Fragment Length Polymorphism with Hind III and Electrophoresis. The data obtained was analysed and the allele frequencies of the -148C>T fibrinogen promoter polymorphism were 78% (wildtype allele) and 22% (mutant allele). On analysing the MAMI collection as a whole, the -148C>T SNP had no significant effect on plasma fibrinogen levels and risk of MI. However, on stratification based on gender and smoking status, certain trends were observed.