[Paroxysmal nocturnal hemoglobinuria and aplastic anemia].

The case of a 14 year-old adolescent girl presenting with paroxysmal nocturnal hemoglobinuria (PNH) associated with aplastic anemia is reported. This disease, rare in children, is characterized by an acquired hemolytic anemia, with abnormal sensitivity to complement: PNH actually affects the bone marrow stem cell. This explains its possible association with any type of malignant blood disease and with aplastic anemia. When aplastic anemia is the first sign of the disease, diagnosis is delayed, due to the possible negative response of the specific Ham's test. Therefore, the proper complications of PNH, especially thromboses, may be misappreciated and poorly managed.