Five (7.4%) patients in the cTnI-negative group had abnormal findings: one had pre-existing Pompe disease-related hypertrophic cardiomyopathy, one had a ventricular septal defect, one had congestive heart failure with moderate mitral regurgitation and tricuspid regurgitation, and two had mitral valve prolapse. This evidence concerns the gene TNNI3 and mitral valve disorder.