This study will investigate Ebstein's anomaly, a congenital abnormality of the tricuspid valve of the heart and try to identify the genetic origins of the disease.

Adults and children 2 years of age and older with Ebstein's anomaly and healthy volunteers may be eligible for this study. Participants undergo the following procedures:

• Blood tests: Three tube of blood will be collected, with the total amount limited to about half a teaspon for each two pounds of body weight.
• Saliva sample collection: A small amount of saliva is collected by spitting into a sterile container.
• Oral (cheek) swab: Cells are collected from the mouth using a soft brush to swab the inside lining of the cheek.
• Electrocardiogram: The electrical activity of the heart is recorded using electrodes placed on the chest.
• Echocardiogram: Heart function is assessed using ultrasound.

The goal of this study is to elucidate the genetic basis for the congenital heart disease (CHD) known as Ebstein's anomaly. These studies complement ongoing research studies using mouse models to recover mutations causing structural heart defects associated with human CHD. By elucidating the underlying genetic causes for Ebstien's anomaly, it may be possible to improve risk assessments as well as facilitate the development of new strategies for prevention and disease management. These studies are important for early diagnosis and the management of complications associated with surviving adults with Ebstein's anomaly, some of whom have undergone surgical correction and others that are unoperated.

• INCLUSION CRITERIA:

Patients who have diagnosed Ebstein's anomaly or tricuspid valve disease in Belarus or Ukraine and their parents will be asked to participate in this study regardless of sex, age, or race. In addition, sex and age matched neighborhood children and their parents will be recruited as controls. There is no known ethnic or racial predilection for Ebstein's anomaly or tricuspid valve disease.

EXCLUSION CRITERIA:

There are no exclusion criteria. This may allow us to discover previously unknown relationships between Ebstein's anomaly and other diseases.