obsolete congenital amegakaryocytic thrombocytopenia

Congenital amegakaryocytic thrombocytopenia

Congenital amegakaryocytic thrombocytopenia (CAMT) is a rare autosomal recessive bone marrow failure syndrome characterized by severe thrombocytopenia, which can progress to aplastic anemia and leukemia. CAMT usually manifests as thrombocytopenia in the initial month of life or in the fetal phase. Typically CAMPT presents with petechiae, cerebral bleeds, recurrent rectal bleeding, or pulmonary hemorrhage. The cause of CAMT is believed to be mutations in the MPL gene coding for thrombopoietin receptor, which is expressed in pluripotent hematopoietic stem cells and cells of the megakaryocyte lineage. CAMT is diagnosed by a bone marrow biopsy and is often initially suspected to be fetal and neonatal alloimmune thrombocytopenia. Two types of Congenital amegakaryocytic thrombocytopenia have been identified with type I being more severe. Treatment is mostly supportive, consisting of multiple platelet transfusions. Hematopoietic stem cell transplantation is the only known cure for CAMT. Once pancytopenia develops, the prognosis is poor. Studies have shown 30% of CAMT patients die from bleeding complications, and another 20% die from complications related to hematopoietic stem cell transplantation.