Genetics plays only a minor role in the current practice of clinical cardiology, despite a widespread appreciation of the familial nature of common cardiovascular disorders. Recent discoveries have elucidated the molecular basis for several heritable forms of cardiomyopathy, dysrhythmia, accelerated atherosclerosis, and structural malformations of the heart, but patients with these conditions are rarely encountered except in a few specialized referral centers. However, the completion of the Human Genome Project and advances in large-scale genome technologies have raised expectations that the determination of genotypes in individual patients will soon become germane to decisions made every day by busy clinicians. Beyond question, recent advances in cardiovascular genetics have provided powerful new insights into disease mechanisms, and a burgeoning literature attests to the enthusiasm with which cardiovascular investigators are seeking to define relationships between genotypes and phenotypes in common, as well as rare, forms of heart disease. This review provides a critical framework within which the clinical cardiologist can understand and evaluate the specific advances in cardiovascular genetics most likely to have practical value for patient management in the near term...