Pyruvate kinase deficiency is a lack of the enzyme pyruvate kinase. This enzyme is used by red blood cells to keep them strong. Without the pyruvate kinase enzyme, red blood cells break down more easily than they should. If too many red blood cells are destroyed, a person may suffer from anemia, a lack of oxygen in the blood that leads to weakness, fatigue, and other symptoms.
As red blood cells are pumped through the lungs, they collect oxygen, which they then release as they travel throughout the rest of the body. Most organs in the human body need oxygen in order to function correctly. In people with pyruvate kinase deficiency, red blood cells break down too easily. Soon there are not enough blood cells to deliver the necessary oxygen.
Pyruvate kinase deficiency can lead to severe complications. The most serious of these is hemolytic anemia, a form of anemia that results from too many red blood cells breaking down too quickly. The byproducts of the cell breakdown build up in the blood and urine, causing dark urine as well as jaundice, a yellowing of the skin and the whites of the eyes. If left untreated, hemolytic anemia can lead to organ failure, especially of the heart. A deficiency of pyruvate kinase is the second most common cause of hemolytic anemia.
People who have pyruvate kinase deficiency may also get gallstones that continue to reoccur after treatment. Gallstones are small rock-like masses that form from the digestive bile in the gallbladder. They can cause inflammation and infection. Gallstones can be treated either with oral medication or through surgery. Most people are able to have their gallbladder removed without causing any health complications.
Having pyruvate kinase deficiency does not necessarily mean that the affected person will suffer from severe symptoms. Some people live relatively normal, healthy lives. Less serious symptoms of pyruvate kinase deficiency include fatigue, pale skin, and mild jaundice.
Those who do develop serious health issues caused by pyruvate kinase deficiency may be helped by a splenectomy. Removing the spleen tends to slow the destruction of red blood cells, though it does not work in all patients. Blood transfusions may also help those with severe anemia.
Pyruvate kinase deficiency is a recessive trait. Therefore both parents must have the defective form of the gene in order to pass it on to their child. It occurs in people of all different ethnicities around the world.