[Pure genetic thrombocytopenia. A new clinical entity]

From a retrospective study of 3,500 platelet kinetic studies, we isolated 51 cases with chronic thrombocytopenia, excessive platelet volume without Döhle bodies and no functional platelet anomalies, normal megakaryocyte count and normal autologous and homologous platelet life-span. These cases were either discovered during the first year of life (i.e. constitutional) or proved as familial (with autosomal dominant transmission). Previous therapies (corticosteroids, immune globulins, androgens, immuno-suppressive agents, splenectomy) were unefficient in all cases as in their relatives.