Recurrence Risks inChildren Having OneParent with a Congenital HeartDisease

THIS REPORT brings together previously published segments"' 2andmakesavailable ourcompleted dataon recurrence risks tooffspring ofparents withseven common andsignificant congenital heart lesions compatible withsurvival toareproductive age.Thetheoretical andempirical bases ofthese studies havebeendeveloped overthepast decade2A4 andwill onlybebriefly reviewed here. Patients andMethods These datahavebeenobtained overthepast15years in Madison, Montreal, Houston andDenver. Ourgoalwasto evaluate personally atleast 100children ofaffected parents foreachoftheseven cardiovascular defects under investigation. Thepersonal evaluation included thedocumenting of thecardiovascular lesion intheparent andoffspring by diagnostic methods appropriate foreachcase. Withtwoexceptions this goalhasbeenachieved. Theexceptions are tetralogy ofFallot andcoarctation oftheaorta. Inthese categories wehaveadded: toour42offspring ofparents with tetralogy, thepublished cases ofTaussig etal.5 andunpublished material ofMcNamara; andtoour62offspring of patients with coarctation oftheaorta, thepublished cases of Zetterqvist.8 Carehasbeentakentoeliminate fromthedatabase families whichhaveMendelian (single gene) syndromes or chromosomal disorders. Thesecases would, ofcourse, introduce abias, mainly reflecting therecurrence risks of single mutant genes. Therecurrence ofheritable chromosomal disorders withcongenital heart diseases isnegligible. Thecurrent distribution ofcategories ofcases being seen in ourclinic isgiven intable 1. Results Table 2summarizes ourrecurrence data andreveals arisk that isrelatively small andwithin therange ofexpectation forrecurrence infirst-degree relatives aspredicted bythe square rootofthepopulation frequency (\/p), oneofthe