Zebra of the Week: Paroxysmal nocturnal hemoglobinuria (PNH)

PNH leads to the impaired production and premature death of blood cells. It's caused by acquired, rather than inherited, genetic changes in the PIGA gene. Usually diagnosed in young adulthood, PNH can lead to recurring episodes of hemolysis, which may be triggered by infections or physical exertion. Signs and symptoms include fatigue, weakness, pallor, SOB, and tachycardia. People with PNH are prone to infections, thrombosis or hemorrhage and are at increased risk of developing leukemia.