[Idiopathic thrombocytopenic purpura in 5 members of a family].

Five cases of idiopathic thrombocytopenic purpura (ITP) appearing on five members of two generations of a family, with autosomal dominant pattern, are presented. The clinico-biologic behaviour of 2 patients (studied and treated by the authors) plus the available data from the 3 others (diagnosed and treated at other hospitals) allowed us to discard any possibility of hereditary non-immunologic thrombocytopenia. The predisposition of ITP patients and their relatives to present clinico-biological features of autoimmune diseases is commented as a possible explanation for the rare forms of familial ITP.