{"topic_id":"companion_species_health_atypical_myopathy_horse","category":"companion-species-health","context":"---\nlicense: permission_granted\ntopic_id: companion_species_health_atypical_myopathy_horse\ncategory: companion-species-health\ntitle: \"Horse (Equus caballus) — Atypical myopathy (hereditary; OMIA-verified species predisposition)\"\nlang: en\nsource: \"OMIA (Online Mendelian Inheritance in Animals, University of Sydney) species-specific hereditary-disorder record, saved verbatim to source_file; C1 substring-verified. Pulled 2026-08-24 from local OMIA database dump.\"\nsource_file: pdf-raw/species-health/horse_atypical_myopathy_4811.txt\ndate_parsed: 2026-08-24\ntokens_estimated: 381\nverification:\n  method: substring_match\n  claims: 3\n  passed: 3\n  date: 2026-08-24\nrecovered: false\npath: companion-species-health/companion_species_health_atypical_myopathy_horse/01_companion_species_health_atypical_myopathy_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: \"Horse (Equus caballus) — Atypical myopathy (hereditary; OMIA-verified species predisposition)\"\n  url: \"https://omia.org/OMIA002480/9796/\"\n  retrieved: \"2026-08-24\"\n  ref: \"OMIA species-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 (species-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.\"\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# Horse (Equus caballus) — Atypical myopathy (hereditary; OMIA-verified species predisposition)\n\nSource: first-hand OMIA (University of Sydney) species-specific hereditary-disorder record, saved verbatim to `source_file`; every claim below is a C1 byte-substring of it.\n\n## Claims\n\n- `Species: Horse (Equus caballus)`\n- `Disorder: Atypical myopathy`\n- `Summary: Sander et al. (2021): \"Several thousands of severe, often letal cases of atypical myopathy (AM) caused by the ingestion of seeds and seedlings of some Acer species have been observed in horses and other equids, occurring in all age groups from the very young to the very old animals [for review see Votion et al. (2020)]. Hypoglycin A (HGA) and methylenecyclopropylglycine (MCPG) are the constituents responsible for this. Newborn foals, however, that do not yet consume green forage themselves and therefore can receive Acer toxins prenatally only via the placenta or postnatally with the milk are apparently very rarely affected by AM. ... we hypothesize that the low concentrations of active maple toxins to be expected in a foal fed with collostrum or milk will only lead to acute disease if there is a special, possibly genetically determined sensitivity.\" Sander et al. (2021) investigated a single foal with severe atypical myopathy and identified an \"extensive loss of function of the enzyme ... long-chain enoyl-CoA hydratase (OMIM 609015, EC 4.2.1.74). The enzyme is, at least in humans, integrated into the mitochondrial trifunctional protein which also harbors the ß-hydroxy-acyl-CoA dehydrogenase and long-chain thiolase. .... Whether a genetic defect could underlie the present case would have had to be proven by appropriate genetic studies. Unfortunately, no suitable tissue was available.\"`\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- 2021. Severe inhibition of long-chain acyl-CoA enoylhydratase (EC 4.2.1.74) in a newborn foal suffering from atypical myopathy. Front Vet Sci — PubMed:PMID34765670 | DOI:10.3389/fvets.2021.765623 — OMIA Phene_Article / Article\n- 2020. Answers to the frequently asked questions regarding horse feeding and management practices to reduce the risk of atypical myopathy. Animals (Basel) — PubMed:PMID32102384 | DOI:10.3390/ani10020365 — OMIA Phene_Article / Article\n- 2024. Large-scale study of blood markers in equine atypical myopathy reveals subclinical poisoning and advances in diagnostic and prognostic criteria. Environ Toxicol Pharmacol — PubMed:PMID39032580 | DOI:10.1016/j.etap.2024.104515 — OMIA Phene_Article / Article\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:609015 (type: trait) — OMIA Group_OMIM (via OMIA_ID)\n- OMIM:600890 (type: gene) — OMIA Group_OMIM (via OMIA_ID)\n- OMIM:143450 (type: gene) — OMIA Group_OMIM (via OMIA_ID)\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- 2021. Severe inhibition of long-chain acyl-CoA enoylhydratase (EC 4.2.1.74) in a newborn foal suffering from atypical myopathy. Front Vet Sci — PubMed:PMID34765670 | DOI:10.3389/fvets.2021.765623 — OMIA Phene_Article / Article\n- 2020. Answers to the frequently asked questions regarding horse feeding and management practices to reduce the risk of atypical myopathy. Animals (Basel) — PubMed:PMID32102384 | DOI:10.3390/ani10020365 — OMIA Phene_Article / Article\n- 2024. Large-scale study of blood markers in equine atypical myopathy reveals subclinical poisoning and advances in diagnostic and prognostic criteria. Environ Toxicol Pharmacol — PubMed:PMID39032580 | DOI:10.1016/j.etap.2024.104515 — OMIA Phene_Article / Article\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:609015 (type: trait) — OMIA Group_OMIM (via OMIA_ID)\n- OMIM:600890 (type: gene) — OMIA Group_OMIM (via OMIA_ID)\n- OMIM:143450 (type: gene) — OMIA Group_OMIM (via OMIA_ID)\n","sources":["companion-species-health — Horse (Equus caballus) — Atypical myopathy (hereditary; OMIA-verified species predisposition)"],"source":{"authority":"companion-species-health","title":"Horse (Equus caballus) — Atypical myopathy (hereditary; OMIA-verified species predisposition)","url":"https://pubmed.ncbi.nlm.nih.gov/34765670/","retrieved":"","ref":"PMID 34765670","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":1056,"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."}