[Mitral valve prolapse study in families].

A study of 82 cases with the prolapse of the mitral valve (PMV) and 169 of their first degree relatives has shown that PMV can be a symptom of a number of hereditary diseases, in the first place of the diseases of the connective tissue. Intrafamilial variations of cardiac changes have been recorded. It is established that the idiopathic PMV is aetiologically variable, which makes it difficult to evaluate the type of heredity of PMV as a whole.