Allogreffe de cellules souches hématopoïétiques dans l'amégacaryocytose congénitale

Congenital amegakaryocytic thrombocytopenia (CAMT) is a rare aetiology of central thrombocytopenia characterised by severe reduction or absence of megakaryocytes in the bone marrow. This disease is caused by mutations in the c-MPL gene encoding for the receptor of thrombopoietin (TPO). The clinical presentation is variable and can often be mistaken for foetal/neonatal alloimmune thrombocytopenia or idiopathic thrombocytopenic purpura. Because of treatment failure, a central thrombocytopenia is suspected. The diagnosis is made by the bone marrow examination, the dosage of TPO and identification of mutations in the c-MPL gene. The outcome is quickly pancytopenia. Description of four new single-center observations of patients treated for CAMT, who underwent allogeneic hematopoietic stem cell transplantation, allowed to focus on this disease and its therapeutic approach. According to the type of c-MPL mutations, a variable outcome has been discussed. Because of haemorrhagic risk and the possibility of a malignant evolution, a stem cell transplantation, being the only curative treatment, must be considered as soon as the diagnosis is established. Gene therapy might be an interesting future prospect.