UC Davis School of Veterinary Medicine Veterinary Genetics Laboratory

Pyruvate Kinase Deficiency

Introduction

Pyruvate kinase deficiency (PKDef) is an inherited hemolytic anemia caused by a defect in the enzyme pyruvate kinase.  Loss of function of this enzyme results in premature death of red blood cells. Affected dogs do not have sufficient quantities of red blood cells to adequately supply the body with oxygen.  Observable signs in affected dogs may include lack of energy, low exercise tolerance and fatigue in dogs that appear otherwise fit. Clinically, dogs with PKDef present with a severe anemia, increased iron levels, increased bone density, may have an enlarged spleen and liver as well as fibrous connective tissue replacement of bone marrow cells. Bone marrow and liver failure typically occur by 5 years of age. The disease is inherited as an autosomal recessive disorder thus both sexes are equally affected and two copies of the defective gene must be present for dogs to be affected. Carrier dogs, those with one defective and one normal copy, show no signs but have half the normal level of pyruvate kinase activity. Breeding two carriers is expected to produce 25% affected offspring and 50% carriers of the disease.

Different breed-specific mutations in the Pyruvate Kinase gene have been identified. The VGL offers tests for the PKDef mutations found in Basenji, Beagle, Pug and West Highland White Terrier breeds to assist owners and breeders in identifying affected and carrier dogs. The test uses DNA collected from buccal (cheek) swabs, thus avoiding blood sample collection. Breeders can use results from the test as a tool for selection of mating pairs to avoid producing affected dogs.

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Allow 2-6 business days for results.

Results reported as:

N/N No copies of the PKDef mutation; dog is normal.
N/K 1 copy of the PKDef mutation; dog is a carrier and unaffected but has half the normal Pyruvate Kinase activity of N/N dogs.
K/K 2 copies of the PKDef mutation; dog is affected.

References:

Gultekin GI, K Raj, P Foureman, S Lehman, K Manhart, O Abdulmalik, U Giger (2012) Erythrocytic pyruvate kinase mutations causing hemolytic anemia, osteosclerosis, and secondary hemochromatosis in dogs. Journal of Veterinary Internal Medicine 26(4):935-944.

Chapman BL, U Giger (1990) Inherited erythrocyte pyruvate kinase deficiency in the West Highland White Terrier. Journal of Small Animal Practice 31:610-616.

Schaer M, JW Harvey, M Calderwoodmays, U Giger (1992) Pyruvate kinase deficiency causing hemolytic anemia with secondary hemochromatosis in a Cairn Terrier. Journal of the American Animal Hospital Association 28:233-239.

 
Veterinary Genetics Laboratory, Tel 530-752-2211, Email VGL