{"topic_id":"companion_breed_health_chihuahua_omia5908_dog","category":"companion-breed-health","context":"---\nlicense: permission_granted\ntopic_id: companion_breed_health_chihuahua_omia5908_dog\ncategory: companion-breed-health\ntitle: \"Chihuahua — Leigh syndrome, NDUFS7-related (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 2026-08-02 from local OMIA database dump.\"\nsource_file: pdf-raw/breed-health/chihuahua_omia5908_5908.txt\ndate_parsed: 2026-08-02\ntokens_estimated: 207\nverification:\n  method: substring_match\n  claims: 6\n  passed: 6\n  date: 2026-08-02\nrecovered: false\npath: companion-breed-health/companion_breed_health_chihuahua_omia5908_dog/01_companion_breed_health_chihuahua_omia5908_dog.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: \"Chihuahua — Leigh syndrome, NDUFS7-related (hereditary; OMIA-verified breed predisposition)\"\n  url: \"https://omia.org/OMIA002840/9615/\"\n  retrieved: \"2026-08-02\"\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\n\n# Chihuahua — Leigh syndrome, NDUFS7-related (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: Chihuahua (Dog)`\n- `Disorder: `\n- `Mode of inheritance: Autosomal recessive`\n- `Clin feat: Christen et al. (2024): Two Jack-Russell Terrier × Chihuahua mixed-breed littermates with Leigh syndrome were investigated. The dogs presented with progressive ataxia, dystonia, and increased lactate levels. Disease onset was at ~4 months of age and the two dogs were euthanized at ~6 months of age due to the severity of their clinical phenotype.`\n- `Defect: yes`\n- `Pathology: Christen et al. (2024): Brain MRI showed characteristic bilateral symmetrical T2 hyperintense lesions, histologically representing encephalomalacia. Muscle histopathology revealed variability in myofiber size and some accumulations of mitochondria.nbsp;Ragged red fibers were not obvious.`\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 398298884 (no symbol in OMIA GeneSynonym) — OMIA Phene_Gene\n- OMIA molecular-genetics note: Christen et al. (2024): \"Whole genome sequencing [of an affected Jack-Russell Terrier × Chihuahua cross] identified a missense variant in a gene associated with human Leigh syndrome, <em>NDUFS7</em>:c.535G&gt;A or p.(Val179Met). The genotypes at the variant co-segregated with the phenotype in the investigated litter as expected for a monogenic autosomal recessive mode of inheritance. [The authors]…\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- 2024. NDUFS7 variant in dogs with Leigh syndrome and its functional validation in a Drosophila melanogaster model. Sci Rep — PubMed:PMID38316835 | DOI:10.1038/s41598-024-53314-7 — 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:601825 (type: gene) — OMIA Group_OMIM (via OMIA_ID)\n- OMIM:256000 (type: trait) — OMIA Group_OMIM (via OMIA_ID)\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","sources":["companion-breed-health — Chihuahua — Leigh syndrome, NDUFS7-related (hereditary; OMIA-verified breed predisposition)"],"source":{"authority":"companion-breed-health","title":"Chihuahua — Leigh syndrome, NDUFS7-related (hereditary; OMIA-verified breed predisposition)","url":"https://pubmed.ncbi.nlm.nih.gov/38316835/","retrieved":"","ref":"PMID 38316835","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":653,"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."}