[Paroxysmal nocturnal hemoglobinuria, a cell surface molecular defect].

Paroxysmal nocturnal haemoglobinuria is an acquired haemolytic anaemia that may develop into aplastic anaemia or myeloid leukaemia. It has recently been shown that paroxysmal nocturnal haemoglobinuria is due to a defective coupling of specific proteins to glycolipids on the cell surface of haematopoietic cells. One of these proteins is decay-accelerating factor (DAF), and the absence of DAF on the surfaces of blood cells leads to the haemolytic symptoms. The molecular biology of DAF and its relationship to paroxysmal nocturnal haemoglobinuria symptoms is described in this brief review. The molecular defect of paroxysmal nocturnal haemoglobinuria is illustrated in a case report.