What Is Pyruvate Kinase Deficiency?
Pyruvate Kinase Deficiency is a hereditary hemolytic anemia that results from a decrease of the essential red blood cell enzyme Pyruvate Kinase (PK). This enzyme helps convert glucose to energy when oxygen is low.
If the amount of the enzyme is low, the red blood cells break down more rapidly than usual, leading to hemolytic anemia. In the late phases of the disease, the bone marrow becomes exhausted and may become scarred, which results in Myelofibrosis. At this point, the anemia is terminal.
The two other fatal complications of Pyruvate Kinase Deficiency are osteosclerosis and liver failure.
Susceptible Dog Breeds
The disease has been reported in the:
The mode of inheritance in the Basenjis and Beagle is autosomal recessive, meaning that a dog must get the defective gene from both parents to develop the disorder. The age at detection of hemolytic anemia is between 6 months and 3 years.5
Diagnosis can be confirmed by measuring red cell Pyruvate Kinase levels. When the bone marrow of dogs with Pyruvate Kinase Deficiency is transplanted with bone marrow from a normal dog, severe anemia is corrected, and hepatic iron accumulation and cirrhosis are prevented. Transplanted dogs do not develop bone disease, a characteristic complication in untreated dogs.6
Breeding plans can be managed through use of laboratory tests that can identify heterozygotes, although some overlap exists in the ranges for enzyme values between homozygote normal and heterozygote carriers. Genetic tests for Pyruvate Kinase Deficiency are available through the University of Pennsylvania at PennGen, OptiGen and VetGen. OFA maintains a voluntary diagnostic service for Basenjis with Pyruvate Kinase Deficiency in cooperation with national breed clubs.4
Pyruvate Kinase Deficiency is described for the first time in three apparently unrelated West Highland white terriers from Ireland and the UK. All three dogs were diagnosed with markedly regenerative but persistent anemia and had been treated for presumed immune-mediated hemolytic anaemia before hereditary erythrocyte Pyruvate Kinase Deficiency was confirmed by breed-specific DNA mutation analysis.
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- Juvet et al. – Erythrocyte Pyruvate Kinase Deficiency In Three West Highland White Terriers In Ireland And The UK