Chihuahua — Bilateral anterior amelia (BAA) (hereditary; OMIA-verified breed predisposition)

--- license: permission_granted topic_id: companion_breed_health_chihuahua_bilateral_anterior_amelia_baa_dog category: companion-breed-health title: "Chihuahua — Bilateral anterior amelia (BAA) (hereditary; OMIA-verified breed predisposition)" lang: en source: "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." source_file: pdf-raw/breed-health/chihuahua_bilateral_anterior_amelia_baa_6299.txt date_parsed: 2026-08-02 tokens_estimated: 147 verification: method: substring_match claims: 5 passed: 5 date: 2026-08-02 recovered: false path: companion-breed-health/companion_breed_health_chihuahua_bilateral_anterior_amelia_baa_dog/01_companion_breed_health_chihuahua_bilateral_anterior_amelia_baa_dog.md source_document: "OMIA — Online Mendelian Inheritance in Animals (University of Sydney)" citation: authority: "OMIA — Online Mendelian Inheritance in Animals (University of Sydney)" title: "Chihuahua — Bilateral anterior amelia (BAA) (hereditary; OMIA-verified breed predisposition)" url: "https://omia.org/OMIA002297/9615/" retrieved: "2026-08-02" ref: "OMIA breed-specific hereditary-disorder records (omia.org), derived from local OMIA database dump; dataset: https://doi.org/10.25910/2AMR-PV70" doc_type: "academic animal-genetics database (breed-specific disorder entries)" needs_review: false

Chihuahua — Bilateral anterior amelia (BAA) (hereditary; OMIA-verified breed predisposition)

Source: 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.

Claims

• Breed: Chihuahua (Dog)
• Disorder: Bilateral anterior amelia (BAA)
• Mode of inheritance: Probably autosomal recessive
• Clin feat: Chevallier et al. (2025): All the [13 affected] the dogs ... were Chihuahua-like (n = 6) or mixed-breed Chihuahuas (n = 7) born with no forelimbs ... . They all had a scapula on both sides and presented a residual fragment of the humerus engaged in the glenoid cavity that varied in length ... . All of them were missing all bones distal to the humerus.
• Defect: yes

Associated gene(s)

Derived 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.

• Gene: Entrez Gene ID 23857650 (no symbol in OMIA GeneSynonym) — OMIA Phene_Gene
• OMIA molecular-genetics note: Chevallier et al. (2025): "Six affected Chihuahuas were whole genome sequenced (WGS) and aligned to the CanFam4 assembly. ... Whole genome sequencing identified three single nucleotide variants [NC_049234.1:g.8891861C &gt; T; NC_049234.1:g.8974204C &gt; T and NC_049234.1:g.9789424G &gt; A] associated with the phenotype. Homozygosity for the variants was observed in 12 out of 13 affected dogs, sugg…

Evidence (references)

Derived 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.

• 1982. An autosomal recessive form of hemimelia in dogs. Vet Rec — PubMed:PMID7186700 | DOI:10.1136/vr.110.6.128 — OMIA Phene_Article / Article
• 2025. The RSPO2 gene is associated with bilateral anterior amelia in Chihuahuas. Mamm Genome — PubMed:PMID40131457 | DOI:10.1007/s00335-025-10123-1 — OMIA Phene_Article / Article

Comparative medicine (human OMIM)

Derived 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.

• OMIM:618021 (type: trait) — OMIA Group_OMIM (via OMIA_ID)
• OMIM:610575 (type: gene) — OMIA Group_OMIM (via OMIA_ID)
• OMIM:618022 (type: trait) — OMIA Group_OMIM (via OMIA_ID)

verification_derived: method: derived_from_dataset source: "OMIA database dump (omia.xml, local); fields Gene/Variant/Article/OMIM" 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."