{"topic_id":"companion_breed_health_belgian_draft_horse_omia2177_horse","category":"companion-breed-health","context":"---\nlicense: permission_granted\ntopic_id: companion_breed_health_belgian_draft_horse_omia2177_horse\ncategory: companion-breed-health\ntitle: \"Belgian Draft (Horse) — Ocular squamous cell carcinoma (hereditary; OMIA-verified breed predisposition)\"\nlang: en\nsource: \"OMIA (Online Mendelian Inheritance in Animals, University of Sydney) breed-specific hereditary-disorder record, saved verbatim to source_file; C1 substring-verified. Pulled 2026-08-23 from local OMIA database dump.\"\nsource_file: pdf-raw/breed-health/belgian_draft_horse_omia2177_2177.txt\ndate_parsed: 2026-08-23\ntokens_estimated: 524\nverification:\n  method: substring_match\n  claims: 7\n  passed: 7\n  date: 2026-08-23\nrecovered: false\npath: companion-breed-health/companion_breed_health_belgian_draft_horse_omia2177_horse/01_companion_breed_health_belgian_draft_horse_omia2177_horse.md\nsource_document: \"OMIA — Online Mendelian Inheritance in Animals (University of Sydney)\"\ncitation:\n  authority: \"OMIA — Online Mendelian Inheritance in Animals (University of Sydney)\"\n  title: \"Belgian Draft (Horse) — Ocular squamous cell carcinoma (hereditary; OMIA-verified breed predisposition)\"\n  url: \"https://omia.org/OMIA000735/9796/\"\n  retrieved: \"2026-08-23\"\n  ref: \"OMIA breed-specific hereditary-disorder records (omia.org), derived from local OMIA database dump; dataset: https://doi.org/10.25910/2AMR-PV70\"\n  doc_type: \"academic animal-genetics database (breed-specific disorder entries)\"\n  needs_review: false\n\nverification_derived:\n  method: derived_from_dataset\n  source: \"OMIA database dump (omia.xml, local); fields Gene/Variant/Article/OMIM\"\n  note: \"Structured fields (gene, variant rsID/protein change, PubMed/DOI references, OMIM cross-link) extracted from OMIA dump and presented with first-hand values; not verbatim prose.\"---\n\n# Belgian Draft (Horse) — Ocular squamous cell carcinoma (hereditary; OMIA-verified breed predisposition)\n\nSource: first-hand OMIA (University of Sydney) breed-specific hereditary-disorder record, saved verbatim to `source_file`; every claim below is a C1 byte-substring of it.\n\n## Claims\n\n- `Breed: Belgian Draft (Horse)`\n- `Disorder: `\n- `Mode of inheritance: Autosomal recessive`\n- `Summary: “Squamous cell carcinoma (SCC) is the most common cancer of the equine eye, and is second to equine sarcoid as the most common tumor of the horse overall. . . . The Haflinger breed, developed in Austria and Northern Italy during the late 19th century, appears to be among those breeds overrepresented for this disease” (Bellone et al., 2017) {contributed by Meredith O’Connell, working under the guidance of Professor Ernie Bailey, 5 March 2019}`\n- `Clin feat: “Squamous cell carcinoma (SCC) is a slow-growing malignant neoplasia of the skin, mucous membranes and mucocutaneous junctions. It is the most common tumor of the eye and adnexa in the horse. Most commonly, the nictitating membrane, nasal canthus, limbus and eyelids are affected. Untreated ocular SCC may invade local soft tissues, the bony orbit, sinuses and brain and less commonly, it may metastasize to the regional lymph nodes, salivary glands and thorax. Limbal involvement can quickly lead to visual impairment and destruction of the globe” (Kaps et al., 2005). {contributed by Meredith O’Connell, working under the guidance of Professor Ernie Bailey, 5 March 2019}`\n- `Defect: yes`\n- `Prevalence: For breeds in which SCC has been reported, the variant allele frequencies reported by Bellone et al. (2017) are 0.25 for Haflingers, 0.21 for Belgians, 0.20 for Rocky Mountain Horses, 0.07 for Percherons, 0.02 for Appaloosas, and zero for Arabian, Clydesdale, Dutch Warmblood, Hanoverian, Oldenburg, Paint Horse, Quarter Horse, Shire, and Thoroughbred. The breeds with zero variant frequency (but in which SCC has been reported) are indicative of the extent to which this variant is incompletely associated with SCC. Knickelbein et al. (2019) reported the frequency of the same variant in the Rocky Mountain breed to be 0.2. {much of the above information was contributed by Meredith O’Connell, working under the guidance of Professor Ernie Bailey, 5 March 2019}`\n## Associated gene(s)\nDerived from OMIA database dump (omia.xml, local); structured field, not verbatim prose. First-hand values below are verbatim substrings of the topic's pdf-raw/omia/<phene_id>.txt source file.\n- Gene: Entrez Gene ID 388942449 (no symbol in OMIA GeneSynonym) — OMIA Phene_Gene\n\n## Evidence (references)\nDerived from OMIA database dump (omia.xml, local); structured field, not verbatim prose. First-hand values below are verbatim substrings of the topic's pdf-raw/omia/<phene_id>.txt source file.\n- 1996. Penetrating keratoplasty for treatment of recurrent squamous cell carcinoma of the cornea in a horse. Journal of the American Veterinary Medical Association — OMIA Phene_Article / Article\n- 2005. Primary invasive ocular squamous cell carcinoma in a horse. Vet Ophthalmol — PubMed:PMID15910373 | DOI:10.1111/j.1463-5224.2005.00358.x — OMIA Phene_Article / Article\n- 1991. Prognostic factors and survival of horses with ocular/adnexal squamous cell carcinoma: 147 cases (1978-1988). J Am Vet Med Assoc — PubMed:PMID2004996 — OMIA Phene_Article / Article\n- 1991. Epidemiologic study of ocular/adnexal squamous cell carcinoma in horses. J Am Vet Med Assoc — PubMed:PMID2004985 — OMIA Phene_Article / Article\n- 1987. Factors influencing morbidity and outcome of equine ocular squamous cell carcinoma. Equine Vet J — PubMed:PMID3608956 — OMIA Phene_Article / Article\n- 1978. Primary ocular squamous cell carcinoma with metastasis in a horse. Vet Med Small Anim Clin — PubMed:PMID247797 — OMIA Phene_Article / Article\n- 2017. A missense mutation in damage-specific DNA binding protein 2 is a genetic risk factor for limbal squamous cell carcinoma in horses. Int J Cancer — PubMed:PMID28425625 | DOI:10.1002/ijc.30744 — OMIA Phene_Article / Article\n- 2015. Limbal squamous cell carcinoma in Haflinger horses. Vet Ophthalmol — PubMed:PMID25312447 | DOI:10.1111/vop.12229 — OMIA Phene_Article / Article\n- 2017. Genetic testing as a tool to identify horses with or at risk for ocular disorders. Vet Clin North Am Equine Pract — PubMed:PMID29103563 | DOI:10.1016/j.cveq.2017.08.005 — OMIA Phene_Article / Article\n- 2018. Genetic risk for squamous cell carcinoma of the nictitating membrane parallels that of the limbus in Haflinger horses. Anim Genet — PubMed:PMID29999543 | DOI:10.1111/age.12695 — OMIA Phene_Article / Article\n- 2020. A missense mutation in damage-specific DNA binding protein 2 is a genetic risk factor for ocular squamous cell carcinoma in Belgian horses. Equine Vet J — PubMed:PMID30903710 | DOI:10.1111/evj.13116 — OMIA Phene_Article / Article\n- 2019. Limbal squamous cell carcinoma in a Rocky Mountain Horse: Case report and investigation of genetic contribution. Vet Ophthalmol — PubMed:PMID30238589 | DOI:10.1111/vop.12612 — OMIA Phene_Article / Article\n- (10 additional references in OMIA)\n\n## Comparative medicine (human OMIM)\nDerived from OMIA database dump (omia.xml, local); structured field, not verbatim prose. First-hand values below are verbatim substrings of the topic's pdf-raw/omia/<phene_id>.txt source file.\n- OMIM:278740 (type: trait) — OMIA Group_OMIM (via OMIA_ID)\n","sources":["companion-breed-health — Belgian Draft (Horse) — Ocular squamous cell carcinoma (hereditary; OMIA-verified breed predisposition)"],"source":{"authority":"companion-breed-health","title":"Belgian Draft (Horse) — Ocular squamous cell carcinoma (hereditary; OMIA-verified breed predisposition)","url":"https://pubmed.ncbi.nlm.nih.gov/15910373/","retrieved":"","ref":"PMID 15910373","doc_type":"official source","source_document":"","verification_file":""},"source_document":"","source_file":"","trust":{"authority_tier":"ungraded","fidelity":"verbatim","license":null,"display_grade":"pending"},"tokens_estimated":1255,"generated_at":null,"tip":"Use /api/v1/topics to discover more topics. /api/v1/nutrient for precise single-point queries. /api/v1/cross_compare for 2-3 standard comparisons."}