Genetic thrombocytopenia with autosomal dominant transmission: a review of 54 cases.

On the basis of a retrospective study of 3600 platelet kinetic studies, we have isolated 54 cases with chronic thrombocytopenia, a normal autologous and homologous platelet lifespan, and increased mean platelet volume without Döhle bodies, the absence of any functional platelet abnormalities, and a normal megakaryocyte count. These cases were either discovered during the first few years of life (i.e. constitutional) and/or were proven to be familial (autosomal dominant transmission). Previous treatments (corticosteroids, immunoglobulins, androgens, immunosuppressor agents, splenectomy) were not effective in any of these cases or in their relatives. A new syndrome can therefore be proposed which can easily be suspected on the basis of platelet kinetic studies performed in cases of early onset, increased platelet volume, failure of corticosteroids or evidence of a familial blood disorder. It can be proved when the autologous platelet life span is demonstrated to be normal in spite of a chronic thrombocytopenia and a normal megakaryocytic count. The recognition of this syndrome will avoid neonatal complications (cephal-haematomas), surgical complications, and the use of expensive and possibly harmful ineffective treatments, both in the propositus and in other abnormal family members. The syndrome is certainly frequent (54 cases are presented here), but the diagnosis is often missed or delayed due to the low risk of haemorrhage. However, it is associated with a certain risk of leukaemia (four cases in three families).