OMIA:002130-8084 : Oculocutaneous albinism, OCA2-related in Xiphophorus hellerii (green swordtail) |
In other species: Mexican tetra , guppy , Japanese medaka , Rhesus monkey , dog , pig , corn snake
Categories: Pigmentation phene
Links to possible relevant human trait(s) and/or gene(s) in OMIM: 203200 (trait) , 611409 (gene)
Links to relevant human diseases in MONDO:
Single-gene trait/disorder: yes
Mode of inheritance: Autosomal recessive
Disease-related: unknown
Key variant known: yes
Year key variant first reported: 2025
Cross-species summary: Tyrosinase-positive oculocutaneous albinism (OCA, type II) is an autosomal recessive disorder in which the biosynthesis of melanin pigment is reduced in skin, hair, and eyes. Renamed from 'Coat colour, oculocutaneous albinism, OCA2-related' [07/09/2024]
Mapping: Xing et al. (2025) mapped albinism to Chr 9: 24,167,249 bp – 24,380,394 bp.
Molecular basis: Xing et al. (2025) "identified a spontaneously occurring albinism phenotype in swordtail fish Xiphophorus hellerii" and identified a large insertion of approximately 480 bp in oca2 as likely causal variant.
Clinical features: Xing et al. (2025): "The albino X. hellerii exhibit no melanophore pigmentation pattern but intact erythrophores and xanthophore pigmentation patterns. In addition, there is no ocular pigmentation and the fish have red eyes."
Associated gene:
| Symbol | Description | Species | Chr | Location | OMIA gene details page | Other Links |
|---|---|---|---|---|---|---|
| oca2 | oculocutaneous albinism II | Xiphophorus hellerii | 9 | NC_045680.1 (24198610..24249217) | oca2 | Ensembl, NCBI gene |
Variants
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WARNING! Inclusion of a variant in this table does not automatically mean that it should be used for DNA testing. Anyone contemplating the use of any of these variants for DNA testing should examine critically the relevant evidence (especially in breeds other than the breed in which the variant was first described). If it is decided to proceed, the location and orientation of the variant sequence should be checked very carefully.
Since October 2021, OMIA includes a semiautomated lift-over pipeline to facilitate updates of genomic positions to a recent reference genome position. These changes to genomic positions are not always reflected in the ‘acknowledgements’ or ‘verbal description’ fields in this table.
| OMIA Variant ID | Breed(s) | Variant Phenotype | Gene | Allele | Variant Type | Variant Effect | Source of Genetic Variant | Pathogenicity Classification* | Reference Sequence | Chr. | g. or m. | c. or n. | p. | Verbal Description | EVA ID | Year Published | PubMed ID(s) | Acknowledgements |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1776 | Oculocutaneous albinism, OCA2-related | oca2 | insertion, gross (>20) | Naturally occurring variant | Not currently evaluated | Xiphophorus_hellerii-4.1 | 9 | approximate 480 bp insertion in the oca2 gene which introduces a premature stop codon | 2025 | 39896652 |
* Variant pathogenicity for single gene diseases as evaluated by an expert panel of the International Society of Animal Genetics (ISAG) Animal Genetic Testing Standardization Standing Committee
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Cite this entry
Nicholas, F. W., Tammen, I., & Sydney Informatics Hub. (2025). OMIA:002130-8084: Online Mendelian Inheritance in Animals (OMIA) [dataset]. https://omia.org/. https://doi.org/10.25910/2AMR-PV70
Reference
| 2025 | Xing, Y., Boswell, W., Parker, J., Du, K., Schartl, M., Lu, Y. : |
| A recessive oca2 mutation underlies albinism in Xiphophorus fish. bioRxiv , 2025. Pubmed reference: 39896652. DOI: 10.1101/2025.01.20.633999. |
Edit History
- Created by Imke Tammen2 on 15 Apr 2025
- Changed by Imke Tammen2 on 15 Apr 2025