Congenital heart disease (CHD) is the most common major birth defect, but l
ittle is known about its cause. More recently, parametric linkage analyses
of rare large families in combination with molecular investigations of gene
tic syndromes characterized in part by CHD are providing new insights into
the molecular genetic cause of structural CHD. This article broadly reviews
what is known about the epidemiology and genetic cause of structural CHD,
with particular emphasis on the newest discoveries and their clinical signi
ficance.