Idiopathic thrombocytopenic purpura (ITP): is there a genetic predisposition?

Idiopathic thrombocytopenic purpura (ITP) is a diagnosis of exclusion. It is unknown, whether familial ITP exists. Familial cases would make a genetic susceptibility for ITP possible. Data of the Pediatric and Adult Registry on Chronic ITP (PARC-ITP) were reviewed and subsequently ITP patients from Basel investigated for cases with a positive family history. In 10 of 445 pediatric patients and in 2 of 21 patients from Basel the family history was positive. A surprisingly high number of ITP patients with a positive family history were identified, indicating the likely existence of a genetic susceptibility for ITP.