--- license: permission_granted topic_id: companion_breed_health_dwarf_long_haired_omia554_rabbit category: companion-breed-health title: "Dwarf, long-haired — Dwarfism, generic (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 2026-08-23 from local OMIA database dump." source_file: pdf-raw/breed-health/dwarf_long_haired_omia554_554.txt date_parsed: 2026-08-23 tokens_estimated: 657 verification: method: substring_match claims: 8 passed: 8 date: 2026-08-23 recovered: false path: companion-breed-health/companion_breed_health_dwarf_long_haired_omia554_rabbit/01_companion_breed_health_dwarf_long_haired_omia554_rabbit.md source_document: "OMIA — Online Mendelian Inheritance in Animals (University of Sydney)" citation: authority: "OMIA — Online Mendelian Inheritance in Animals (University of Sydney)" title: "Dwarf, long-haired — Dwarfism, generic (hereditary; OMIA-verified breed predisposition)" url: "https://omia.org/OMIA000299/9986/" retrieved: "2026-08-23" 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
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."---
Dwarf, long-haired — Dwarfism, generic (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: Dwarf, long-hairedDisorder:Mode of inheritance: Autosomal incomplete dominantSummary: Robinson (1958, pp. 343-346) provides an extensive summary of this form of proportionate dwarfism. The effect of the mutant dw allele on a wide range of traits was reported by Crary and Sawin (1949), Sawin and Dietz (1950), Sawin and Curran (1952), and in three 1955 papers by Latimer and Sawin. The results of Carneiro et al. (2017) imply that small size in dwarf rabbits results from a large effect, loss-of-function (LOF) mutation in HMGA2 combined with polygenic selection. Bovo et al. (2025) provide evidence for a polygenic architecture underlying small size in rabbits, influenced by a few major loci.Clin feat: As reported by Green et al. (1934): The [homozygous] dwarfs of this stock are born alive and occasionally they are capable of nursing, but so far, none of them has lived longer than a few days. They are delicately formed and to outward appearance are fully developed except for the bones of the calvarium, which, as a rule, are incompletely calcified.brCarneiro et al. (2016) summarise the phenotype information reported by Robinson (1958): The emdwarf/em allele is recessive lethal. Homozygotes (emdw/dw/em) are smaller than litter mates and exhibit a characteristic swollen head, tiny ears, and are usually called peanuts ... . Peanuts are viable up to the time of birth but typically die within a few days of birth. Heterozygotes (emDw/dw/em) reach ∼2/3 of the size of wild-type litter mates (emDw/em/emDw/em) and in adulthood are typically under 1 kg in body weight, have compact and rounded bodies, a disproportionately larger head when compared to the rest of the body, small ears, and a short snout due to altered craniofacial development ... . Several resources suggest that the altered craniofacial development may predispose dwarf rabbits to an increased risk to develop dental disease (e.g. Harcourt-Brown, 1997; Wegner, 1997; van Caelenberg et al., 2008; Koroleva and Titova, 2022).nbsp;Defect: yesPathology: The pathology in individuals homozygous for the dwarf mutation leads to death.nbsp;Control: Breeding of two animals that are both heterozgyous for the dwarf mutation should be avoided. For the breeding of dwarf rabbits, each breeding pair should include an animal heterozygous for the dwarf mutation (dwarf rabbit) and an animal that does not have the dwarf mutation. This will avoid the birth of non viable homozygous dwarfs and result in the birth of 50% viable (heterozygous) dwarfs and 50% normal sized rabbits.
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 394535807 (no symbol in OMIA GeneSynonym) — OMIA Phene_Gene
- OMIA molecular-genetics note: Carneiro et al. (2017) showed "that the dwarf allele constitutes a ~12.1 kb deletion overlapping the promoter region and first three exons of the HMGA2 gene leading to inactivation of this gene." Very interestingly, mutation in this same gene is associated with body-size variation in dogs (<a href="../../../../../../OMIA001968/9615/">OMIA:001968-9615</a>) and horses (<a href="../../../../../../OMI…
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.
- 1940. A dwarf mutation in the rabbit: the constitutional influence on homozygous and heterozygous individuals. J Exp Med — PubMed:PMID19871001 — OMIA Phene_Article / Article
- 1990. Hereditary C8-alpha-gamma deficiency associated with dwarfism in the rabbit. Journal of Heredity — OMIA Phene_Article / Article
- 1997. Zur Problematik der Zwergkanninchen-Zucht [Problematic aspects of breeding dwarf rabbits]. Dtsch Tierarztl Wochenschr — PubMed:PMID9289403 — OMIA Phene_Article / Article
- 1981. In vitro culture of rabbit growth plate chondrocytes. 2. Chondrodystrophic mutants. Growth — PubMed:PMID6458543 — OMIA Phene_Article / Article
- 1934. A lethal dwarf mutation in the rabbit with stigmata of endocrine abnormality. Science — PubMed:PMID17840734 | DOI:10.1126/science.79.2056.487 — OMIA Phene_Article / Article
- 1955. Morphogenetic studies of the rabbit. XIII. The influence of the dwarf gene upon organ size and variability in race X. Anat Rec — PubMed:PMID13292775 — OMIA Phene_Article / Article
- 1957. Morphogenetic studies of the rabbit. XV. Measurements of the digestive tube and of its parts in normal and dwarf rabbits of race X. Anat Rec — PubMed:PMID13509179 — OMIA Phene_Article / Article
- 1958. Genetic studies of the rabbit. Bibliographia Genetica — OMIA Phene_Article / Article
- 1941. Genetic linkage in the rabbit. Proc Natl Acad Sci U S A — PubMed:PMID16588495 | DOI:10.1073/pnas.27.11.519 — OMIA Phene_Article / Article
- 1949. Morphogenetic studies in the rabbit. VI. Genetic factors influencing the ossification pattern of the limbs. Genetics — PubMed:PMID17247330 | DOI:10.1093/genetics/34.5.508 — OMIA Phene_Article / Article
- 1950. Morphogenetic studies of the rabbit. IX. Masking of prenatal growth gradients in adults. Moderne Biologie (eds Griineberg, H. and Ulrich, W.) — OMIA Phene_Article / Article
- 1952. Genetic and physiological background of reproduction in the rabbit. 1. The problem and its biological significance. Journal of Experimental Zoology — OMIA Phene_Article / Article
- (12 additional references in OMIA)
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:600768 (type: gene) — OMIA Group_OMIM (via OMIA_ID)
- OMIM:600509 (type: gene) — OMIA Group_OMIM (via OMIA_ID)