Role of sarcomeric gene polymorphisms on left ventricular dysfunction in coronary artery disease patients

Background

Coronary artery disease (CAD) is a major cardiac disease in humans. Many CAD patients develop left ventricle dysfunction (LVD), leading to congestive heart failure. Mutations in several genes including those encoding sarcomeric proteins such as MYBPC3, TNNT2, and TTN are common genetic cause of hereditary cardiac myopathies. An intronic 25-bp deletion in MYBPC3 at 3’ region is associated with dilated (DCM) and hypertrophic (HCM) cardiomyopathies in Southeast Asia. We sought to determine the role of MYBPC3 25bp, TNNT2 5bp and TNN 18bp ins/del polymorphisms on LVD in CAD patients.

Methods and results

The study included 200 healthy controls and 988 consecutive patients with angiographically confirmed CAD. Among them, 253 with reduced ejection fraction (LVEF <45%) were categorized as having LVD. MYBPC3 25bp, TNNT2 5bp and TNN 18bp ins/del polymorphisms were determined by polymerase chain reaction. Our results showed that MYBPC3 25bp deletion was significantly associated with CAD as well as LVD (healthy controls v/s CAD; p value = 0.003; OR=4.08, healthy controls v/s LVD; p value < 0.0001; OR=6.67 and Non-LVD v/s LVD; p value = 0.031; OR=1.67). The TNNT2 5bp and TNN 18bp polymorphisms were not found to be associated with CAD (Pvalue=0.580, OR=0.88; Pvalue=0.795, OR=0.91; respectively) or LVD (Pvalue=0.146, OR=1.35; Pvalue=0.935, OR=0.97 respectively) when compared to controls.

Conclusions

The frequency of MYBPC3 DW genotype and D allele was associated with LVD implying that genetic variants of MYBPC3 encoding mutant structural sarcomeric protein could increase susceptibility to left ventricular dysfunction. Therefore, 25bp deletion in MYBPC3 may represent a genetic marker for cardiac failure in CAD patients.