Genetic aspects of Ebstein anomaly and related heart diseases

Ebstein anomaly is a congenital heart disease, which is characterized by the presence of atrialized portion of the right ventricle, formed as a result of displacement of the tricuspid valve leaflets into the right ventricle and their partial adherence to the underlying myocardium. Atrialized portion in the right ventricle occupies the space between the fibrous annulus of the right atrioventricular orifice and the functional annulus of tricuspid valve, which represents a zone of closure of free (non-adherent to the underlying myocardium) edges of its leaflets. Ebstein anomaly is very rarely isolated, and can be combined with a number of heart diseases and be an integral part of hereditary syndromes. Currently, the role of genetic research in the investigation of the etiology of human diseases as well as understanding of the relationship between different diseases is increasing. The review presents literature data on the combination of Ebstein anomaly with other heart diseases (congenital heart diseases, Wolf-Parkinson-White syndrome, cardiomyopathies, including left ventricular noncompaction), inter alia, within the scope of hereditary syndromes (Noonan syndrome, 8p deletion syndrome, 18q deletion syndrome, 1p36 deletion syndrome, Pierre Robin syndrome). Genetic factors (gene and chromosomal mutations) lying at the core of Ebstein anomaly, as well as heart diseases combined with it, are highlighted. The analysis of published data suggests that Ebstein anomaly is a monogenic disease, and is characterized by allelic and locus genetic heterogeneity. The combination of Ebstein anomaly with other heart diseases is based on their genetic linkage.