Role of genetic analyses in cardiology: part II: heritability estimation for gene searching in multifactorial diseases.

Genetic testing is a growing discipline in clinical practice, and it is being used to make treatment decisions and to counsel patients. Before genetic testing can be done, reliable information needs to be available on which genes are involved in a disease. Research into genetic determinants of disease often is based on articles reporting the magnitude of the heritability of disease. Here, we address limitations in the use of heritability as a point of departure, such as a basis for power calculations, for genetic studies.