The commonest mode of inheritance of congenital hea disease is

Ref Harrison 19 th ed pg 1516 The most common bih defects are cardiovascular in origin. These malformations are due to complex multifactorial genetic and environ- mental causes. Recognized chromosomal aberrations and mutations of single genes account for <10% of all cardiac malformations. Congenital hea disease (CHD) complicates ~1% of all live bihs in the general population--about 40,000 bihs/year--but occurs more frequently in the offspring (about 4-10%, depending on maternal CHD type) of women with CHD. Owing to the remarkable surgical advances over the last 60 years, >90% of afflicted neonates and children now reach adulthood; women with CHD may now frequently successfully bear children after competent repairs.