Pyruvate Kinase Deficiency (PKDef) in Labrador Retrievers

Quick Summary

Pyruvate kinase deficiency in Labrador Retrievers is a chronic, severe hemolytic anemia caused by defective production of the enzyme pyruvate kinase. Signs in affected dogs may include lethargy, low exercise tolerance, and fatigue.
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Phenotype: Observable signs in affected dogs may include lethargy, low exercise tolerance, and fatigue. Clinically, affected dogs present with severe anemia, increased bone density, enlarged spleen and liver as well as fibrous connective tissue replacement of bone marrow cells. Signs usually appear between 4 months and 2 years of age, and prognosis is generally poor for affected individuals, with complete liver failure typically occurring by 5 years of age.

Mode of Inheritance: Autosomal recessive

Alleles: N = Normal, K = Pyruvate kinase deficiency

Breeds appropriate for testing: Labrador Retriever, Labradoodle

Explanation of Results:

  • Dogs with N/N genotype will not have pyruvate kinase deficiency and cannot transmit this pyruvate kinase deficiency variant to their offspring.
  • Dogs with N/K genotype are not expected to show signs of pyruvate kinase deficiency but have half the normal level of pyruvate kinase activity, and are carriers of this variant. They may transmit this pyruvate kinase deficiency variant to 50% of their offspring. Matings between two carriers are predicted to produce 25% pyruvate kinase deficiency-affected puppies.
  • Dogs with K/K genotype will have pyruvate kinase deficiency, prognosis is poor. 

Results of this test can be submitted to the OFA (Orthopedic Foundation for Animals)

Price

$50 one test per animal
$30 as additional test (same animal)

*$65 flat fee per dog for HNPK test (No additional discounts applied)

Panels Available
Additional Details

Pyruvate kinase deficiency (PKDef) is a chronic, severe hemolytic anemia caused by defective production of the enzyme pyruvate kinase. Low levels of this enzyme result in premature death of red blood cells and insufficient supply of oxygen to the body’s cells. Observable signs in affected dogs may include lethargy, low exercise tolerance, and fatigue. Clinically, affected dogs present with severe anemia, increased bone density, enlarged spleen and liver as well as fibrous connective tissue replacement of bone marrow cells. Signs usually appear between 4 months and 2 years of age, and prognosis is generally poor for affected individuals, with complete liver failure typically occurring by 5 years of age.

PKDef in Labrador Retrievers is caused by a single nucleotide mutation (c.799C>T) in exon 7 of the Pyruvate Kinase L/R (PKLR) gene. The mode of inheritance for this disease is autosomal recessive, which means that males and females are equally affected and that two copies of the mutation are needed to cause PKDef. Screening of a random set of Labradors Retrievers at the VGL determined that the PKLR disease allele is rare in this breed, with frequency less than 1%.

Testing for PKDef assists clinicians with diagnosis of PKDef and helps breeders identify carriers among the breeding population. Carrier dogs, those with one defective and one normal copy, show no signs of disease but have half the normal level of pyruvate kinase activity. Breeding between two carriers is not recommended because 25% of the offspring are expected to be affected and 50% are expected to be carriers of the disease.

Turnaround Time
5-10 business days

Species

Dog

Type of Test

Results Reported As
Test Result Pyruvate Kinase Deficiency

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. If bred to another carrier, 25% of offspring are predicted to be affected.

K/K

2 copies of the PKDef mutation. Dog is affected.

References

Gultekin, G.I., Raj, K., Foureman, P., Lehman, S., Manhart, K., & Giger, U. (2012). Erythrocytic pyruvate kinase mutations causing hemolytic anemia, osteosclerosis, and secondary hemochromatosis in dogs. Journal of Veterinary Internal Medicince, 26(4), 935-944. doi: 10.1111/j.1939-1676.2012.00958.x