Coronary artery disease is influenced by both environmental and genetic factors. Current evidence shows that the CD40-CD40 ligand (CD40-CD40L) system plays a crucial role in the development, progression and outcome of acute coronary syndrome. A single nucleotide polymorphism (SNP) located at position –1 in the Kozak sequence of the CD40 gene (rs1883832; C>T) has been associated with the development of acute coronary syndrome. The purpose of the study was to explore the association between the C/T (–1) single nucleotide polymorphism in the CD40 gene and myocar-dial infarction (MI) in the Tunisian male population.

A total of 273 unrelated Tunisian patients with MI and 219 healthy controls were genotyped using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Clinical parameters such as fasting serum total cholesterol, high-density lipoprotein cholesterol (HDL-C), triglycerides, and plasma glucose were detected by autoanalyzer assay. Weight, height and blood pressure (BP) were measured and body mass index (BMI) was calculated.

Patients with MI had significantly higher frequency of the TT genotypes compared to controls (12.5% vs. 5.9%; OR=1.43, 95% CI: 1.08 – 1. 89, p=0.011). The MI patient group showed a significant higher frequency of the T allele compared to the controls (0.33 vs. 0.26; OR=1.45, 95% CI: 1.09 – 1.94, p=0.008). The association between the C/T (–1) single nucleotide polymorphism in the CD40 gene and MI remained significant after adjustment for other well-established cardiovascular risk factors.

Our study suggests that C/T (–1) single nucleotide polymorphism in the CD40 gene might contribute to the susceptibility to MI in the Tunisian male population. Further replication with larger numbers, and populations of different ethnicities, are needed to confirm our finding.