Pyruvate kinase deficiency
PK deficiency; PKD
Pyruvate 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 in all parts of the body. For example, they can help break down the foods we eat ...
Hemolytic 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 ...
Causes
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 trait, disorder, or disease can be passed down through families. An autosomal recessive disorder me...
There 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 .
(G6PD) deficiency
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a condition in which red blood cells break down when the body is exposed to certain drugs or t...
PKD 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...
-
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.
-
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...
-
Neurologic condition, called
kernicterus
, that affects the brain
Kernicterus
Bilirubin encephalopathy is a rare neurological condition that occurs in some newborns with severe jaundice.
- Fatigue, lethargy
-
Pale skin (
pallor
)
Pallor
Paleness is an abnormal loss of color from normal skin or mucous membranes.
-
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 gender....
- 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.
-
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...
-
CBC
CBC
A complete blood count (CBC) test measures the following:The number of red blood cells (RBC count)The number of white blood cells (WBC count)The tota...
- Genetic testing for mutation 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 a certai...
-
Osmotic fragility
Osmotic fragility
Osmotic fragility is a blood test to detect whether red blood cells are more likely to break down.
-
Pyruvate kinase
activity
Pyruvate kinase
The pyruvate kinase test measures the level of the enzyme pyruvate kinase in the blood. Pyruvate kinase is an enzyme found in red blood cells. It he...
- 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, ...
Exchange 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...
Someone who had a splenectomy should receive the pneumococcal vaccine at recommended intervals. They also should receive preventive antibiotics until age 5.
Pneumococcal vaccine
All content below is taken in its entirety from the CDC Information Statement (VIS): www. cdc. gov/vaccines/hcp/vis/vis-statements/pcv13. htmlCDC rev...
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 (this is a symptom of many severe illnesses).
- 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.
References
Mentzer WC. Pyruvate kinase deficiency and disorders of glycolysis. In: Orkin SH, Fisher DE, Ginsburg D, Look AT, Lux SE, Nathan DG, eds. Nathan and Oski's Hematology and Oncology of Infancy and Childhood . 8th ed. Philadelphia, PA: Elsevier Saundres; 2015:chap 17.
Segel GB. Enzymatic defects. In: Kliegman RM, Stanton BF, St Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2015:chap 463.1.
Review Date: 10/27/2015
Reviewed By: Chad Haldeman-Englert, MD, FACMG, Fullerton Genetics Center, Asheville, NC. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.