[Genetics of congenital heart diseases]

New insights into the genetics of congenital heart diseases in human beings have been drawn these past years. The identification of genes for heart defects have led to a new clinical approach of these malformations in children and their families. These progresses have been made with the help of positional cloning as well as with the analysis of mouse models. These findings also yielded a new complexity in understanding the development of cardiac defects and led to revise the different classifications for congenital heart defects. Pediatric cardiologists have also improved their efficiency in defining cardiac phenotypes in affected individuals and in pedigrees with recurrent malformations. Genetic heterogeneity has made the molecular approach of a given defect difficult. In addition, intrafamilial variability still has scarce explanations. Finally, the contribution of epigenetic factors has to be kept in mind in specific conditions such as twin gestations. Clinical consequences of these findings remain at the present time limited for the patients themselves but in particular cases, genetic counseling has been dramatically improved.