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Canine Mendelian disease record

Glanzmann Thrombasthenia, Type I (Discovered in the Great Pyrenees)

Glanzmann Thrombasthenia, Type I (Discovered in the Great Pyrenees). Autosomal recessive. Observed in 2 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:001000-9615
Autosomal recessive
Source dataset
Sniff Atlas v1.0.1 / DOI
The human connection

A model of human Glanzmann thrombasthenia 1

Dogs with this condition carry a change in ITGA2B. In people, changes in the same gene cause Glanzmann thrombasthenia 1. 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: A bleeding syndrome characterized by spontaneous mucocutaneous bleeding and an exaggerated response to trauma due to a constitutional thrombocytopenia

In humans it is also called: BDPLT2, GT, deficiency of GP 2B 3A complex, Diacyclothrombopathia 2B 3A, Glanzmann thrombasthenia type A.

MONDO:0031332 OMIM 273800

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

More specifically called Glanzmann thrombasthenia.

Molecular genetics

By cloning and sequencing a very likely comparative candidate gene (based on the homologous human disorder), Lipscomb et al. (2000) reported "a 14-base insertion in exon 13 and defective splicing of intron 13 in the alphaIIb gene [ITGA2B]" which "disrupted the fourth alphaIIb calcium-binding domain, caused a shift in the reading frame and resulted in a premature termination codon. Possible consequences of this mutation include decreased alphaIIb mRNA stability and production of truncated alphaIIb protein that lacks the transmembrane and cytoplasmic domains and a large portion of the extracellular domain". Boudreaux et al. (2001) reported a "single nucleotide change at position G1193 (1100) . . . detected in exon 12 of the gene encoding for platelet GPIIb [ITGA2B] in 2 affected Otterhounds. . . . This nucleotide change would result in substitution of histidine for aspartic acid at position 398 (367) within the third calcium-binding domain of GPIIb" Haysome et al. (2016) reported "a single nucleotide change at position 1264 in exon 13 (C1264T), [that] resulted in a nonsense mutation (CGA > TGA) at the codon encoding arginine (R) at position 422 (R422X ...) in two affected mix-breed dogs. Christopherson et al. (2017) reported in a conference proceeding a likely causal variant in a Golden Retriever as a "single nucleotide deletion at position (1924delC) in ITGA2B ... . This change results in a frameshift and premature termination codon 24 bases downstream."

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 273800 Gene · OMIM 607759

Source: OMIA (Nicholas, Tammen & the Sydney Informatics Hub), entry OMIA:001000-9615, 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 18.

  1. Clinical assessment of primary hemostasis: A review. · Top Companion Anim Med · 2023 · PMID 37673175
  2. Gene therapy for inherited bleeding disorders. · Semin Thromb Hemost · 2021 · PMID 33636747
  4. Identification of a single base deletion in the glycoprotein IIB gene causing Glanzmann thrombasthenia in a Golden Retriever. · American College of Veterinary Pathologists. · 2017

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 Glanzmann Thrombasthenia, Type I (Discovered in the Great Pyrenees) 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 Glanzmann Thrombasthenia, Type I (Discovered in the Great Pyrenees) looks like in your dog's breed.
Carrier frequency by breed

Top 2 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%1%2%
Great Pyrenees0.58% · n 1,985
Yorkshire Terrier<0.1% · n 8,367
n = 10,352 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 Glanzmann Thrombasthenia, Type I (Discovered in the Great Pyrenees) is measured; phenotype outcome depends on penetrance and modifiers.
▸ Full table with Wilson 95% confidence intervals
Breed Carrier frequency n tested
Great Pyrenees 0.58% 1,985
Yorkshire Terrier <0.1% 8,367

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

Scope of this record

Scope

This record carries the breed-level carrier frequencies from the Donner 2023 cohort. Penetrance data (the fraction of at-risk dogs that develop the phenotype) is not yet quantified for this disease in the Sniff Atlas v1.0.1. The OMIA entry is the authoritative reference for the clinical phenotype, inheritance pattern, and gene assignment.

Predicted disease relevance at the per-dog level is UNPROVEN. The carrier frequency is measured; phenotype outcome depends on 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:001000-9615.

  • 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:001000-9615 · Donner et al. 2023