{"topic_id":"companion_breed_health_arab_horse_silver_dapple_horse","category":"companion-breed-health","context":"---\nlicense: permission_granted\ntopic_id: companion_breed_health_arab_horse_silver_dapple_horse\ncategory: companion-breed-health\ntitle: \"Arab (Horse) — Silver dapple (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/arab_horse_silver_dapple_2833.txt\ndate_parsed: 2026-08-23\ntokens_estimated: 236\nverification:\n  method: substring_match\n  claims: 5\n  passed: 5\n  date: 2026-08-23\nrecovered: false\npath: companion-breed-health/companion_breed_health_arab_horse_silver_dapple_horse/01_companion_breed_health_arab_horse_silver_dapple_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: \"Arab (Horse) — Silver dapple (hereditary; OMIA-verified breed predisposition)\"\n  url: \"https://omia.org/OMIA001438/9796/\"\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# Arab (Horse) — Silver dapple (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: Arab (Horse)`\n- `Disorder: Silver dapple`\n- `Mode of inheritance: Autosomal dominant`\n- `Summary: The Silver coat color, also called Silver dapple, is characterized by dilution of the black pigment (eumelanin) in the hair. This phenotype shows an autosomal dominant inheritance. The effect of the mutation is most visible in the long hairs of the mane and tail, which are diluted to a mixture of white and gray hairs (Brunberg et al. 2006). A likely causal variant responsible for silver dilution was identified in the PMEL gene in 2006 (Brunbereg et al., 2006; Reissmann et al., 2007). See also: a href=https://www.omia.org/OMIA000733/9796/OMIA:000733-9796/a Multiple Congenital Ocular Anomalies (MCOA) [IT thanks Mary Katherine Easterwood, working under the guidance of Professor Ernie Bailey, for contributions to this entry in April 2022]`\n- `Defect: yes`\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: PMEL17 (Entrez Gene ID 4143454) — OMIA Phene_Gene / GeneSynonym\n- OMIA molecular-genetics note: Brunberg et al. (2006) reported that \"a missense mutation in exon 11 [of PMEL17] changing the second amino acid in the cytoplasmic region from arginine to cysteine (Arg618Cys) . . . showed complete association with the Silver phenotype across multiple horse breeds [Icelandic horse; American miniature; Rocky mountain horse; Morgan horse; Swedish warmblood, Ardenne], and was not found among non-Silv…\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- 1953. Silver dapple, a unique colour variety among Shetland ponies. Journal of Heredity — OMIA Phene_Article / Article\n- 2006. A missense mutation in PMEL17 is associated with the Silver coat color in the horse. BMC Genetics — PubMed:PMID17029645 | DOI:10.1186/1471-2156-7-46 — OMIA Phene_Article / Article\n- 2009. Genetics. It's a bull's market. Science — PubMed:PMID19390037 | DOI:10.1126/science.1173880 — OMIA Phene_Article / Article\n- 2009. Molecular tests for coat colours in horses. J Anim Breed Genet — PubMed:PMID19912415 | DOI:10.1111/j.1439-0388.2009.00832.x — OMIA Phene_Article / Article\n- 2007. Two SNPs in the SILV gene are associated with silver coat colour in ponies. Anim Genet — PubMed:PMID17257181 | DOI:10.1111/j.1365-2052.2006.01553.x — OMIA Phene_Article / Article\n- 2010. Pleiotropic effects of pigmentation genes in horses. Anim Genet — PubMed:PMID21070283 | DOI:10.1111/j.1365-2052.2010.02116.x — OMIA Phene_Article / Article\n- 2010. [Molecular basis and applicability in equine color genetics]. Yi Chuan — PubMed:PMID21513164 — OMIA Phene_Article / Article\n- 2011. Mutations in or near the transmembrane domain alter PMEL amyloid formation from functional to pathogenic. PLoS Genet — PubMed:PMID21949659 | DOI:10.1371/journal.pgen.1002286 — OMIA Phene_Article / Article\n- 2013. Equine multiple congenital ocular anomalies and silver coat colour result from the pleiotropic effects of mutant PMEL. PLoS One — PubMed:PMID24086599 | DOI:10.1371/journal.pone.0075639 — OMIA Phene_Article / Article\n- 2016. Distribution of coat-color-associated alleles in the domestic horse population and Przewalski's horse. J Appl Genet — PubMed:PMID27194311 | DOI:10.1007/s13353-016-0352-7 — OMIA Phene_Article / Article\n- 2021. Multiple congenital ocular anomalies in a silver coat Missouri Fox Trotter stallion. Tierarztl Prax Ausg G Grosstiere Nutztiere — PubMed:PMID34666370 | DOI:10.1055/a-1581-4810 — OMIA Phene_Article / Article\n- 2012. Coat colour and sex identification in horses from Iron Age Sweden. Ann Anat — PubMed:PMID22154005 | DOI:10.1016/j.aanat.2011.11.001 — OMIA Phene_Article / Article\n- (1 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:155550 (type: gene) — OMIA Group_OMIM (via OMIA_ID)\n","sources":["companion-breed-health — Arab (Horse) — Silver dapple (hereditary; OMIA-verified breed predisposition)"],"source":{"authority":"companion-breed-health","title":"Arab (Horse) — Silver dapple (hereditary; OMIA-verified breed predisposition)","url":"https://pubmed.ncbi.nlm.nih.gov/17029645/","retrieved":"","ref":"PMID 17029645","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":1023,"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."}