[Genetic heterogeneity and complexity of congenital heart defects].

Congenital heart defects are the most common birth defects, they account for approximately one third of all cases. They are clinically heterogeneous, vary widely in severity, treatability and prognosis and may occur as part of multiple developmental disorders, such as chromosome aberrations, microdeletion syndromes and monogenic diseases, or as isolated defects. Syndromic forms account for 25-40%, isolated forms for 60-75% of all cases. With conventional cytogenetic and next-generation molecular genetic methods, numerous genetic alterations have been identified in evolutionarily highly conserved genes of transcriptional regulators, signaling molecules and structural proteins, which are critical to normal cardiogenesis, mostly in cases with syndromic congenital heart defects. On the other hand, the genetic cause can be detected only in around 11% of isolated heart defects. The survival rate and life quality of patients with congenital heart defects have improved significantly in the last decades thanks to the remarkable development of prenatal, postnatal diagnostics as well as of heart and thoracic surgery of cardiovascular diseases. Since the number of patients, living into adulthood and reproductive age, is constantly increasing, the better understanding of the genetics of congenital heart defects may be crucial for the diagnosis, prognosis and positive family planning of patients. Orv Hetil. 2018; 159(17): 661-670.