Three cases in a family of hereditary thrombocytopenic purpura are reported. Each case presented as an idiopathic thrombocytopenic purpura (ITP)-like syndrome. Careful family history revealed that some other members had similar symptom, and the mode of inheritance was autosomal dominant (Fig. 1). The platelet counts of the three family members ranged from 0.8×104/μl to 8.0×104/μl. The major platelet membrane glycoprotein was normally represented in case 3 (Fig. 2). All patients revealed increased PAIgG and PBIgG and slightly increased platelet volume (Table 1). The autoantibodies of the three patients did not recognize same antigen (Fig. 3). Aggregation by ADP, collagen and ristocetin was all normal in case 3 (Fig. 4). Cases 1 and 3 exhibited normal vWF: Ag (Fig. 5).
These results suggest that the thrombocytopenia in this family is related to an immunological mechanism.
