Familial Immune Thrombocytopenia. Report of 16 Cases and Literature Review

Abstract

Immune thrombocytopenia (ITP) is an acquired disorder that generally occurs in sporadic individuals, but a few patients are grouped in families. The aims of the present study were: 1) to perform a retrospective descriptive study of a series of patients with familial ITP, and 2) to perform a literature review on familial ITP.We studied 16 ITP patients, from 8 families, selected by using the general established exclusion criteria as well as at least one of the following additional positive criteria: the finding of autoantibodies on the platelet surface, a short platelet survival in the kinetic study, or a clear therapeutic response to immunosupressors or splenectomy. Moreover, we studied 60 patients with familial ITP previously reported in the literature, selected by using the same diagnostic criteria as for our patients. The patient's characteristics of familial ITP were not substantially different from those of sporadic ITP patients. The small number of patients reported in the literature suggests that, familial ITP has been underdiagnosed. We recommend considering the possible diagnosis of familial ITP when a familial thrombocytopenia has no demonstrable genetic cause, especially if there are other autoimmune disorders in the family. Moreover, to obtain a true diagnosis in these families we recommend applying the additional positive criteria mentioned above besides the exclusion diagnostic criteria.

Deciphering the genetic basis of immune thrombocytopenia: current evidence for genetic predisposition in adult ITP

“…Although familial ITP is a very rare disease, only 2% of ITP cases reported to be familial, 29 there is also some anecdotal evidence for a hereditary component in ITP development. Besides descriptive reports of ITP in monozygotic twins or families with multiple affected members 30 , recent family-based linkage studies used high-throughput sequencing methods that enabled the identification of germ line mutations in genes such as IKZF1 31 or TNFRSF13B 32 as predisposing factors for familial ITP. The phenomenon of hereditary ITP has to be clearly separated from defined genetic disorders associated with thrombocytopenia, including common variable immunodeficiency, myosin heavy-chain 9–related disorders, autoimmune lymphoproliferative syndrome related to defects in the FAS pathway, and Wiskott-Aldrich syndrome/X-linked thrombocytopenia.…”