Paroxysmal nocturnal hemoglobinuria: the biochemical defects and the clinical syndrome.

Paroxysmal nocturnal hemoglobinuria is a disorder characterized by the lack of membrane proteins affixed to the membrane by an anchor dependent upon phosphatidyl inositol, suggesting that some acquired abnormality in the metabolism of this class of proteins is basic to the disease. Most of the clinical symptoms can be explained by the lack of these proteins. However, much work is needed to understand completely the relationship of the biochemical facts and the clinical syndrome.