The fetal genes MYH6 and MYH7, are essential for the growth and morphogenesis of cardiac tissue during embryonic development; and an overexpression of both MYH6 and MYH7 has been shown to be significantly associated with atrial septal-defects, arrhythmia, cardiomyopathy, myocarditis, microvascular-dysfunctions, hypertrophy, and heart failure [7,18,46,51]. The gene discussed is MYH7; the disease is cardiac arrhythmia.