This invention relates to the production of dual models of Congenital Heart Defects and Hypertrophic Cardiomyopathy with the use of mice which are genetically modified by transgenic (gene-knockout) techniques. The present invention produces knockout mice that show multiple cardiovascular malformations which will serve as a model of cardiovascular diseases for the screening of potential drugs against ventricular remodeling, malignant arrhythmias, primary pulmonary hypertension, and degenerative valvular diseases, and congenital heart disease.