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Canine Mendelian disease record

Glycogen storage disease VII (GSD VII) or Phosphofructokinase (PFK) Deficiency

Glycogen storage disease VII (GSD VII) or Phosphofructokinase (PFK) Deficiency. Autosomal recessive. Observed in 5 of 266 breeds tested in the Sniff Atlas, with measured carrier frequencies drawn from 242,665 dogs (Donner 2023). Per-dog phenotype outcome depends on penetrance, modifiers, and environment; the carrier frequencies below describe variant prevalence, not disease incidence.

OMIA identifier
OMIA:000421-9615
Autosomal recessive
Source dataset
Sniff Atlas v1.0.1 / DOI
The human connection

A model of human glycogen storage disease VII

Dogs with this condition carry a change in PFKM. In people, changes in the same gene cause glycogen storage disease VII. That makes affected dogs a naturally-occurring model of the human disease, and it is part of why studying dogs moves medicine forward for everyone. It does not mean your dog has the human disease. It means the two share an underlying biology.

In people, the disease is described as: Muscle phosphofructokinase (PFK) deficiency (Tarui's disease), or glycogen storage disease type 7 (GSD7), is a rare form of glycogen storage disease characterized by exertional fatigue and muscular exercise intolerance. It occurs in childhood.

In humans it is also called: GSD7, GSDVII, Glycogen Storage Disease Type 7, glycogen storage disease type 7, glycogen storage disease type VII.

MONDO:0009295 OMIM 232800

Mapped from OMIA via the human disease's OMIM entry to the Mondo Disease Ontology (Monarch Initiative, CC-BY 4.0). Sniff renders this as a model-of link; the canine disease remains the subject of this page.

About this disease

From OMIA's curated record

Documented in OMIA (Online Mendelian Inheritance in Animals). This describes the disease as recorded in the published literature, not a prediction for any individual dog. As of 2026-06-03.

Summary

Phosphofructokinase (PFK) deficiency is an inherited enzyme deficiency causing hemolytic crises and exertional myopathy. Genetic tests are available to detect causative mutations, which have beend identical in the English springer spaniel, American cocker spaniel, Whippet and Wachtelhund. Edited by Vicki N. Meyers-Wallen, VMD, PhD, Dipl. ACT and updated by IT [April 2022]

Clinical features

Presenting signs include muscle cramps, exercise intolerance, and a mild increase in creatine kinase. Affected dogs can also present in hemolytic crisis with hemoglobinuria and bilirubinuria after excessive excitement, exercise, or hyperthermia. During a crisis, the dog can develop severe anemia, icterus, fever, lethargy, and anorexia. This anemia is regenerative, usually resolving within several days. Affected animals have a normal life span, usually maintaining a normal PCV but persistent bilirubinuria and reticulocytosis. Variable muscle wasting, hepatosplenomegaly, and increased total body iron stores have also been reported (Gerber et al., 2009).

Molecular genetics

By cloning and sequencing a very likely comparative candidate gene (based on the homologous human disorder), Smith et al. (1996) identified the causal mutation as "a nonsense mutation in the penultimate exon of the [muscle type phosphofructokinase] M-PFK gene [now called PFKM], leading to rapid degradation of a truncated (40 amino acids) and therefore unstable M-PFK protein". The single base pair mutation (G2228A) is identical in the English springer spaniel, American cocker spaniel and Whippet (Gerber et al., 2009). Inal Gultekin et al. (2012) reported a different mutation (a point mutation (c.550C>T; p.Arg184Trp) in the same gene as being causative in Wachtelhund dogs.

Pathology

PFK, a cytosolic enzyme in the anaerobic pathway, is composed of three subunits: muscle (M-PFK), liver (L-PFK), and platelet (P-PFK) types. These subunits are present in different proportions in different tissues. Affected dogs lack PFK in skeletal muscle, and have only 20% of normal PFK activity in erythrocytes, which is from L-PFK and P-PFK expression (Gerber et al., 2009). Their PFK-deficient erythrocytes have hemoglobin with high oxygen affinity that helps to compensate for transient but severe anemic episodes (Skibild et al., 2001). Hemolytic crises in affected dogs are precipitated by hyperventilation, hyperthermia, and associated alkalemia, which induce intravascular hemolysis (Skibild et al., 2001).

Prevalence

Canine PFK deficiency has been reported in the USA, the UK, and Europe. Of 600 English Springer Spaniels screened in the USA, 14% were carriers and 6% were affected (Skibild, 2001).

Control

Dogs of breeds or families in which the disease has been reported should be tested prior to pursuing athletic work such as field trials.

Genetic testing

There is a PCR-based test available to detect the mutation in the English springer spaniel, American cocker spaniel and Whippet. A second mutation has been identified in Wachtelhund breed.

Human analog

OMIA links this condition to its human counterpart in OMIM (Mendelian Inheritance in Man), the place to read across to the deeper human literature for the same biology.

Disease · OMIM 232800 Gene · OMIM 610681

Source: OMIA (Nicholas, Tammen & the Sydney Informatics Hub), entry OMIA:000421-9615, doi:10.25910/2AMR-PV70 (CC-BY 4.0).

Signs & cross-references

How it presents

Catalogued in the Mondo disease ontology (the cross-species disease identity used by the Monarch Initiative) as glycogen storage disease VII (MONDO:0009295).

Phenotype terms: Human Phenotype Ontology + Mammalian Phenotype Ontology; disease terms: Mondo (Monarch Initiative). Cross-references curated by OMIA (doi:10.25910/2AMR-PV70, CC-BY 4.0).

The evidence

Published references

The peer-reviewed papers behind this disease, curated by OMIA. Starred entries are OMIA-designated landmark papers. Showing 6 of 22.

  3. Hereditary phosphofructokinase deficiency in wachtelhunds. · J Am Anim Hosp Assoc · 2011 · PMID 21311071

References curated by OMIA (Nicholas, Tammen & the Sydney Informatics Hub), doi:10.25910/2AMR-PV70 (CC-BY 4.0). Full list at the OMIA entry.

Predict a litter

Set each parent's status for Glycogen storage disease VII (GSD VII) or Phosphofructokinase (PFK) Deficiency and see the odds for their puppies. Single recessive variant, exact Mendelian math.

Parent A
Parent B
NNClear
NmCarrier
NmCarrier
mmAffected
Clear25%
Carrier50%
Affected25%

These are the genetic odds for one known variant, not a promise: a real litter varies around them, and penetrance or other genes can change whether the condition ever appears. Use it to avoid pairing two carriers and to keep a line healthy, not to engineer a dog. Inheritance mode per OMIA.
Your breed

See what Glycogen storage disease VII (GSD VII) or Phosphofructokinase (PFK) Deficiency looks like in your dog's breed.
Carrier frequency by breed

Top 5 well-sampled breeds (n ≥ 50)

Maximum per breed across variants in the Donner 2023 cohort, with . The list below is split into well-sampled breeds (n ≥ 50 tested) and small-sample breeds (n < 50, where the Wilson CI typically spans more than 20 percentage points and frequencies should not be compared directly to the well-sampled entries). Frequencies are population-level, not per-litter or per-line.

0%3%5%
English Springer Spaniel1.9% · n 751
Cocker Spaniel<0.1% · n 1,881
Chihuahua<0.1% · n 4,273
Siberian Husky<0.1% · n 9,035
American Staffordshire Terrier<0.1% · n 42,793
n = 58,733 dogs · Donner et al. 2023 carrier-screening cohort · Sniff Atlas
Each bar is one well-sampled breed; the whisker is its Wilson 95% CI, and fainter bars have wider intervals. Frequencies are population-level, not per-litter. Carrier status for Glycogen storage disease VII (GSD VII) or Phosphofructokinase (PFK) Deficiency is measured; phenotype outcome depends on penetrance and modifiers.
▸ Full table with Wilson 95% confidence intervals
Breed Carrier frequency n tested
English Springer Spaniel 1.9% 751
Cocker Spaniel <0.1% 1,881
Chihuahua <0.1% 4,273
Siberian Husky <0.1% 9,035
American Staffordshire Terrier <0.1% 42,793

261 additional breeds in the Donner 2023 cohort were tested but showed no carriers.

Penetrance

From genotype to phenotype

Carrier status is not the same as disease status. Penetrance is the fraction of at-risk dogs that develop the phenotype. The Donner 2023 S4 table tracks this for 1 variant(s) underlying this disease in the cohort.

At-risk dogs evaluated
1
Phenotype confirmed
0
Penetrance range
not yet quantifiable

Fewer than 20 at-risk dogs evaluated; too few to state a penetrance figure.

Predicted disease relevance at the per-dog level is UNPROVEN. The carrier frequency is measured; phenotype outcome is governed by penetrance, environment, and modifier loci. Consult a veterinarian for clinical interpretation.

How to cite this record

Citations

If you use this record in published work, cite the Sniff Atlas (the published dataset that carries the breed-level carrier frequencies) and the upstream sources:

  • Sniff Atlas v1.0.1 for the per-breed carrier frequencies:

    Gehring, M. (2026). Sniff Atlas v1.0.1. Zenodo. https://doi.org/10.5281/zenodo.20566358. CC-BY 4.0.

  • OMIA for the disease definition, inheritance, and gene assignment:

    Nicholas, F. W., & Tammen, I. (2024). OMIA. Sydney Informatics Hub, The University of Sydney. https://doi.org/10.25910/2AMR-PV70. Entry: OMIA:000421-9615.

  • Donner et al. 2023 for the breed × variant carrier-frequency cohort:

    Donner, J., Freyer, J., Davison, S., Anderson, H., Blades, M., Honkanen, L., et al. (2023). Genetic prevalence and clinical relevance of canine Mendelian disease variants in over one million dogs. PLOS Genetics, 19(2), e1010651. https://doi.org/10.1371/journal.pgen.1010651.

Full citation formats (BibTeX, RIS, CITATION.cff) at sniff.world/cite.

Related

Related

Last updated
Sources: Sniff Atlas v1.0.1 · OMIA OMIA:000421-9615 · Donner et al. 2023