Are congenital heart defects hereditary?

They can be.: Multifactorial inheritance is seen with most congenital defects (including cardiac), meaning they more likely to recur in future pregnancies if the first one is affected (or if the mother or father is affected). Obviously, syndromic cases will have stronger genetic inheritance and more mendelian vertical transmission.

Depends on variables: There are a few syndromes with high frequency of specific heart defects that can have inheritance risk up to 50%. Most, however, are part of a complex inheritance pattern with around 5% risk.This 5% would include any pattern of congenital heart defect, not necessarily the same one.