Congenital thrombotic thrombocytopenic purpura associated with moyamoya syndrome in a 3-year-old girl: a case report.

A 3-year-old girl who presented with anemia, thrombocytopenia, and recurrent strokes is described. The cerebral angiography revealed moyamoya vasculopathy. Her younger brother also had anemia and thrombocytopenia but no neurologic abnormalities. Both children had severe deficiency of ADAMTS13 (A Disintegrin And Metalloprotease with Thrombospondin like domain activity) confirming the diagnosis of congenital thrombotic thrombocytopenic purpura. The children responded well to regular fresh-frozen plasma infusions. This report expands the spectrum of hematologic diseases associated with moyamoya syndrome. Unexplained thrombocytopenia, especially in the presence of neurologic symptoms, should prompt an evaluation for ADAMTS13deficiency. The diagnosis has significant implications not only for therapy but also for genetic counseling.