Paroxysmal nocturnal hemoglobinuria (PNH) is a subtype of
hemolytic anemia. Paroxysmal nocturnal hemoglobinuria is characterized by a decreased number of red blood cells (
anemia), and the presence of blood in the urine (hemoglobinuria) and plasma (hemoglobinemia). It usually happens at night after sleeping. It's common that number of white blood cells and platelets are also reduced.
PNH blood cells are broken down due to no surface proteins that protect the cell from destructive components in the blood. The surface proteins need to anchor on the cell membrane, however, a key anchor component is not synthesized in PNH blood cells because the cells are deficient in a required enzyme known as PIG-A. The PIG-A defective is the direct cause of PNH.
PNH is an acquired genetic disorder, not an inherited disease, though. The affected blood cell clone passes the altered PIG-A to all its descendants, including red cells, white cells, lymphocytes, and platelets.
The most danger of paroxysmal nocturnal hemoglobinuria is thrombosis of large intra-abdominal veins. Most patients who die of the disease die of thrombosis
Paroxysmal nocturnal hemoglobinuria is due to deficient in an enzyme PIG-A required for the biosynthesis of cellular anchors. It is an acquired genetic disorder
