Pyruvate Kinase Deficiency

What is pyruvate kinase deficiency?

Pyruvate kinase deficiency (PKD) is a genetic blood disorder. The disease affects red blood cells (RBCs), which carry oxygen throughout the body. If your child has PKD, he or she has low levels of an enzyme called pyruvate kinase in their RBCs. Without this enzyme, red blood cells cannot maintain their structure and break down faster than normal red blood cells, leading to lower numbers of red blood cells (anemia).

If your child has PKD, the reason he or she has low levels of the pyruvate kinase enzyme is because his or her PKLR gene is not working correctly. We are proud to be the only children’s hospital in the United States offering a clinical trial to test whether gene therapy—putting a correct copy of the PKLR gene into your child’s cells—is a safe and effective treatment for PKD.

What are the symptoms of pyruvate kinase deficiency?

The symptoms of PKD can include:

  • Pale skin (pallor).
  • Yellowing of the eyes and skin (jaundice).
  • Extreme tiredness.
  • Rapid heart rate (tachycardia).

PKD is caused by a mutation in the PKLR gene, which provides instructions for making the pyruvate kinase enzyme.

How do we treat pyruvate kinase deficiency at Stanford Medicine Children’s Health?

There is currently no cure for PKD. If your child has a severe case of PKD, he or she may require frequent blood transfusions. Chronic blood transfusions can increase the risk of iron overload and exposure to hepatitis B/C and can lead to a poor quality of life.

That’s why we’re excited about a new treatment option that will be available soon: gene therapy to treat PKD. Gene therapy involves inserting a normal PKLR gene into your child’s blood-making cells, and then putting those cells back into your child through an infusion. The hope is that the cells with the normal PKLR gene will go on to make red blood cells that have a healthy amount of the pyruvate kinase enzyme. We were the only hospital in the United States to offer a clinical trial testing gene therapy to treat PKD, and we are planning to offer this treatment again soon, either as part of another clinical trial or as a therapy approved by the U.S. Food and Drug Administration.

Stem cell transplantation is not routinely used to treat PKD.