Erythrocyte Pyruvate Kinase Deficiency

Alleles: N = Normal, K = PK deficiency

  • N/N No copies of PK deficiency mutation. (Your cat is not a carrier of this disease)

  • N/K 1 copy of PK deficiency mutation. The cat will live a normal life but carries a broken allele. This allele will be passed to kittens if breeding.

  • K/K 2 copies of PK deficiency mutation. Your feline is or will be affected and the severity of symptoms cannot be predicted. All offsprings will get PK deficiency.


Testing can be done by UCDAVIS at https://vgl.ucdavis.edu/test/pk-deficiency-cat or Optimal selection at https://optimal-selection.com/products/optimal-selection-feline.

Signs & Symptoms: Pale mucous membranes, Lethargy, Lack of appetite, Weight loss, Icterus (jaundice), Abdominal enlargement, Diarrhea

The resulting anaemia is often mild and intermittently detectable or may not become evident until the cat is older (if ever), so there is not usually cause for immediate concern. Indeed some cats never show clinical signs associated with PKDef. Signs to look out for are lethargy and inappetence. Stressful situations may cause symptoms to develop.


The only treatment available is a bone marrow transplant. This treatment is very expensive and life threatening.


Due to wanting to limit the gene pool unless the kitten is of perfect features we will not allow that kitten to be released for breeding if they are a carrier of the broken allele. We also will at this time not breed N/K to another N/K or K/K due to the treatment being so new and risky.

Pyruvate Kinase is a disorder that causes anemia due to the breakdown of red blood cells, this is caused due to a mutation of the PKLR gene. The anemia can be intermittent as well as the age of onset is random, and clinical signs are also random. The disease is inherited as an autosomal recessive trait, so only cats with two copies of the defective gene are affected. It only works like a Yin and Yang, one cannot function properly without the other.

Any carriers of a single allele are okay to breed against a clean non-carrier. No we do NOT allow kittens who are carriers to be sold back into the pool with breeding rights. If we so choose to breed the broken gene it will be done within our home or within our small circle of scientific breeders for further study in hopes we can release the line back into the gene pool clean and with out any issues.

Any kitten with a single PKDEF allele will live a normal happy life without any conflicts or issues due to this broken gene! Links are provided below with more useful and helpful information regarding this disease and the genes behind how it works.

Red blood cells (RBCs or erythrocytes): Cells that carry oxygen throughout the body


Anemia: A condition in which the blood has lower-than-normal levels of RBCs or hemoglobin


Hemoglobin: A protein that helps RBCs carry the oxygen your body needs


Hemolytic anemia: A type of anemia that is caused by the early breakdown of RBCs in the bloodstream or by the spleen


Hemolysis: The breakdown of RBCs, which leads to the release of hemoglobin into the blood and production of bilirubin


Chronic: Lasting a long time


Catalyze: To increase the rate of a chemical reaction


Enzyme: A protein that catalyzes chemical reactions that occur inside the body


Gene mutation: A permanent change in the DNA sequence of a gene, altering the gene’s ability to make a protein and causing the protein to stop working properly


Deficiency: A shortage of something


PKR (pyruvate kinase in RBC): The pyruvate kinase enzyme


Glycolysis: The process of RBCs converting glucose (sugar) into pyruvate and ATP


ATP: The primary source of energy for cells