[A familial aggregation of cases with abnormally located chordae in the heart]

Two families with abnormally situated chordae in the heart ventricles are described. This anomaly is found in children as well as in their parents, young persons 19 to 37 years of age, sometimes in older persons. The appearance of this morphologic sign in different generations of the same families and its vertical transmission suggests genetic determination with monogenic autosomal-dominant way of inheritance, but a polygenic inheritance cannot be excluded.