Familial de Lange syndrome: Report of three cases in a sibship

Familial de Lange syndrome with 3 affected siblings in a sibship of 4 is described. The parents were phenotypically normal. No parental consanguinity was demonstrated. The karyotypes of the affected siblings were normal. Although the etiology of the syndrome is obscure, it is likely that it consists of a heterogeneous group of clinical entities. Morphologic criteria may be useful in distinguishing the sporadic cases from the familial ones.