Pyruvate kinase deficiency
PK deficiency; PKDPyruvate kinase deficiency is an inherited lack of the enzyme pyruvate kinase, which is used by red blood cells. Without this enzyme, red blood cells break down too easily, resulting in a low level of these cells (hemolytic anemia).
Enzyme
Enzymes are complex proteins that cause a specific chemical change. For example, they can help break down the foods we eat so the body can use them....
Read Article Now Book Mark ArticleHemolytic anemia
Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. Normally, red ...
Read Article Now Book Mark ArticleCauses
Pyruvate kinase deficiency (PKD) is passed down as an autosomal recessive trait. This means that a child must receive a non-working gene from each parent to develop the disorder.
Autosomal recessive
Autosomal recessive is one of several ways that a genetic trait, disorder, or disease can be passed down through families. An autosomal recessive dis...
Read Article Now Book Mark ArticleThere are many different types of enzyme-related defects of the red blood cell that can cause hemolytic anemia. PKD is the second most common cause, after glucose-6-phosphate dehydrogenase (G6PD) deficiency.
Glucose-6-phosphate dehydrogenase
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a condition in which red blood cells break down when the body is exposed to certain medicines ...
Read Article Now Book Mark ArticlePKD is found in people of all ethnic backgrounds. But, certain populations, such as the Amish, are more likely to develop the condition.
Symptoms
Symptoms of PKD include:
- Low count of healthy red blood cells (anemia)
Anemia
Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. Different type...
Read Article Now Book Mark Article - Swelling of the spleen (splenomegaly)
Splenomegaly
Splenomegaly is a larger-than-normal spleen. The spleen is an organ in the upper left part of the belly.
Read Article Now Book Mark Article - Yellow color of the skin, mucous membranes, or white part of the eyes (jaundice)
Jaundice
Jaundice is a yellow color of the skin, mucus membranes, or eyes. The yellow coloring comes from bilirubin, a byproduct of old red blood cells. Jau...
Read Article Now Book Mark Article - Neurologic condition, called kernicterus, that affects the brain
Kernicterus
Bilirubin encephalopathy is a rare neurological condition that occurs in some newborns with severe jaundice.
Read Article Now Book Mark Article - Fatigue, lethargy
- Pale skin (pallor)
Pallor
Paleness is an abnormal loss of color from normal skin or mucous membranes.
Read Article Now Book Mark Article - In infants, not gaining weight and growing as expected (failure to thrive)
Failure to thrive
Failure to thrive refers to children whose current weight or rate of weight gain is much lower than that of other children of similar age and sex....
Read Article Now Book Mark Article - Gallstones, usually in the teens and older
Exams and Tests
The health care provider will perform a physical exam and ask about and check for symptoms such as an enlarged spleen. If PKD is suspected, tests that will likely be ordered include:
Enlarged spleen
Splenomegaly is a larger-than-normal spleen. The spleen is an organ in the upper left part of the belly.
Read Article Now Book Mark Article- Bilirubin in the blood
Bilirubin
The bilirubin blood test measures the level of bilirubin in the blood. Bilirubin is a yellowish pigment found in bile, a fluid made by the liver. Bi...
Read Article Now Book Mark Article - CBC blood test
CBC blood test
A complete blood count (CBC) test measures the following:The number of white blood cells (WBC count)The number of red blood cells (RBC count)The numb...
Read Article Now Book Mark Article - Genetic testing for changes in the pyruvate kinase gene
- Haptoglobin blood test
Haptoglobin blood test
The haptoglobin blood test measures the level of haptoglobin in your blood. Haptoglobin is a protein produced by the liver. It attaches to hemoglobi...
Read Article Now Book Mark Article - Osmotic fragility
Osmotic fragility
Osmotic fragility is a blood test to detect whether red blood cells are more likely to break down.
Read Article Now Book Mark Article - Pyruvate kinase activity
Pyruvate kinase
The pyruvate kinase test measures the level of pyruvate kinase enzyme in the blood. Pyruvate kinase is an enzyme found in red blood cells. It helps ...
Read Article Now Book Mark Article - Stool urobilinogen
Treatment
People with severe anemia may need blood transfusions. Removing the spleen (splenectomy) may help reduce the destruction of red blood cells. But, this does not help in all cases. In newborns with a dangerous level of jaundice, the provider may recommend an exchange transfusion. This procedure involves slowly removing the infant's blood and replacing it with fresh donor blood or plasma.
Splenectomy
Spleen removal is surgery to remove a diseased or damaged spleen. This surgery is called splenectomy. The spleen is in the upper part of the belly, ...
Read Article Now Book Mark ArticleExchange transfusion
Exchange transfusion is a potentially life-saving procedure that is done to counteract the effects of serious jaundice or changes in the blood due to...
Read Article Now Book Mark ArticleSomeone who had a splenectomy should receive the pneumococcal vaccine at recommended intervals. They also should receive preventive antibiotics until age 5.
Pneumococcal vaccine
Content below is taken in its entirety from the CDC Information Statement (VIS): www. cdc. gov/vaccines/hcp/vis/vis-statements/pcv. html
Read Article Now Book Mark ArticleSupport Groups
More information and support for people with PKD condition and their families can be found at:
- National Library of Medicine - MedlinePlus -- medlineplus.gov/genetics/condition/pyruvate-kinase-deficiency/
- National Organization for Rare Disorders -- rarediseases.org/rare-diseases/pyruvate-kinase-deficiency/
- NIH Genetic and Rare Diseases Information Center -- rarediseases.info.nih.gov/diseases/7514/pyruvate-kinase-deficiency
Outlook (Prognosis)
The outcome varies. Some people have few or no symptoms. Others have severe symptoms. Treatment can usually make symptoms less severe.
Possible Complications
Gallstones are a common problem. They are made of too much bilirubin, which is produced during hemolytic anemia. Severe pneumococcal disease is a possible complication after splenectomy.
When to Contact a Medical Professional
See your provider if:
- You have jaundice or anemia.
- You have a family history of this disorder and are planning to have children. Genetic counseling can help you know how likely it will be that your child would have PKD. You can also learn about tests that check for genetic disorders, such as PKD, so that you can decide if you'd like to have these tests.
Genetic counseling
Genetics is the study of heredity, the process of a parent passing certain genes on to their children. A person's appearance, such as height, hair co...
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References
Gallagher PG. Hemolytic anemias: red blood cell membrane and metabolic defects. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 147.
Remiker AS, Brandow AM. Enzymatic defects. In: Kliegman RM, St. Geme JW, Blum NJ, et al, eds. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia, PA: Elsevier; 2025:chap 512.
Review Date: 12/31/2023
Reviewed By: Anna C. Edens Hurst, MD, MS, Associate Professor in Medical Genetics, The University of Alabama at Birmingham, Birmingham, AL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.