Transporter polymorphism and risk of MI in the Maltese population

Abstract

Serotonin (5-HT) is a mild platelet agonist and its plasma concentration is regulated by the serotonin transporter, 5-HTT, present on platelet surfaces. The 5-hydroxytryptamine transporter linked polymorphic region (5-HTTLPR) is a functional polymorphism in the promoter region of the SLC6A4 which codes for 5-HTT. It involves an imperfect size polymorphism of 43-44bp thus giving rise to a long (L) or short (S) allele. Previous studies have shown conflicting evidence between the different genotypes and the risk of myocardial infarction (MI). The aim of this study was to determine if any genotype of the 5-HTTLPR polymorphism (alone or in combination with other known risk factors) is associated with an increased risk of MI in the Maltese population. Genotyping for the 5- HTTLPR by sizing was carried out on 1064 Maltese samples from the Maltese Acute Myocardial Infarction (MAMI) study which includes both cases with a first MI, relatives of cases and controls. Odds ratios with a 95% confidence interval were calculated using SPSS. The 5-HTTLPR polymorphism alone was not associated with increased risk of MI. However, combined analysis of genotype and smoking showed a slightly increased risk of MI in smokers with the SS genotype.