Thrombocytopenia Inherited as an Autosomal Dominant Trait.

IN CONTRAST to the hereditary disorders of red cells and white cells, inherited disorders of the platelets appear to be rare. Among the few reports of hereditary thrombocytopenia,1'4 some lack essential history or supporting laboratory data. Those which present more convincing evidence display a remarkable variety cf clinical features and genetic patterns. Only the so-called Aldrich syndrome7 emerges as a definite clinical and genetic entity. This report concerns a family of eight members of a kindred in which four generations have been afflicted with a hemorrhagic diathesis which appears to be the result of mild thrombocytopenia inherited as an autosomal dominant trait. FAMILY REPORT The occurrence of bleeding symptoms and thronibocytopenia in this kindred is summarized in pedigree form in figure 1. Our first contact with this family was made in 1958, when V-31 was referred to this center for evaluation of thronlbocytopenia which had not responded to splenecton#{236}y. In 1962, V-29 was referred for evaluation of abnormal bruisabil-ity, and when she was found to be thrombocytopenic, a study of the entire family, which consists of eight members of generations IV and V, revealed thrombocytopenia in her father (IV-23) and in two of her remaining four siblings (V-28, V-33). Of the five family members found to be thronibocytopenic the date when abnormal bleeding began was apparent in only one instance (V-29); here it was first noted at age 14. The others recalled symptoms beginning in " childhood. " These symptoms included increased bruisability in all five, frequent spontaneous epistaxes in two of five, and prolonged bleeding and " slow " wound healing in two of five. In V-28, prolonged bleeding, sufficient to require resuturing, followed a tonsillectomy, but cir-cumcisions at birth in IV-23, V-28 and V-31, and an appendectomy and a tooth extraction in IV-23, were tolerated without complications. There is no other history of surgical procedures, and the only potentially serious bleeding manifestations related were two self-limited episodes of hematuria in V-28, which were presumed to be the result of a flank contusion. There is no history of petechial skin lesions, or of swollen, discolored, or painful joints. No one in the family has ever required hospitalization or received blood transfusions for hemorrhage, and the bleeding symptoms have caused concern sufficient to result in medical consultation in only one instance (V-29). IV-24 and V-29 related a history of mild eczema, and V-28 and V-31 have suffered from recurrent generalized …