Family history in assessing the risk for progression of mitral valve prolapse. Report of a kindred.

Mitral valve prolapse (MVP) consists of prolapse or billowing of the mitral leaflet(s) into the left atrium during ventricular systole associated with a mid-to-late systolic click and/or a late systolic murmur. Thoracic skeletal abnormalities, progressive mitral regurgitation, ventricular arrhythmia, and sudden death have been associated with an autosomal dominant "MVP syndrome." The discovery of MVP in an asymptomatic 8-year-old boy led to a family investigation with subsequent delineation of age-related, progressive, mitral valve disease through four generations of the kindred. Although generally considered a benign syndrome, obtaining a full family history is important in assessing the risk for progression of mitral valve disease in affected family members.