COL6A1 and ventricular septal defect: In addition, the variants in the COL6A1, CREBBP, DOCK6, EOGT, EP300, LRP2, MYBPC3, MYH7, SEMA3C, and ZFPM2 genes are associated with characteristic phenotypes of FSV, such as atrial septal defect, ventricular septal defect, small left heart syndrome, transposition of the great arteries, and double outlet right ventricle occurring at high frequency in patients.