OMIA:000131-9796 : Blood group system K in Equus caballus (domestic horse) |
In other species: turkey , pig , goat
Categories: Haematopoietic system phene
Links to possible relevant human trait(s) and/or gene(s) in OMIM: 617922 (gene) , 111300 (trait)
Single-gene trait/disorder: yes
Disease-related: no
Key variant known: yes
Year key variant first reported: 2026
Cross-species summary:
Each blood group system consists of a set of blood types, each of which corresponds to a particular antigen (usually a glycoprotein) on the surface of red blood cells. The different types within a system are the result of the action of different alleles at a locus that usually encodes an enzyme that catalyses the creation of the feature of the glycoprotein unique to that type, e.g. the presence of a particular sugar at the end of a short chain of sugars.
In horses, the blood group system K is caused by variants in GYPA.
Species-specific symbol: K-, Ka
Mapping: Sandberg (1974) reported linkage between the K blood group locus and the 6-PGD locus in horses.
Molecular basis: Mackowski et al. (2026) "identified GYPA (glycophorin A) as the most promising candidate gene [for the serological blood types (Ka or K-)]. Resequencing its entire coding sequence revealed the presence of a dinu-cleotide missense variant in exon 3 (ENSECAT00000026370.3:c.145_146delinsAT; p.Asp49Ile), which is predicted to potentially alter the function of the GYPA protein. Genotyping this variant in a large, breed-diverse cohort, which included family-based samples, confirmed perfect cosegregation between the identified GYPA missense substitution and serological K blood grouptyping results."
Associated gene:
| Symbol | Description | Species | Chr | Location | OMIA gene details page | Other Links |
|---|---|---|---|---|---|---|
| GYPA | glycophorin A (MNS blood group) | Equus caballus | 2 | NC_091685.1 (94044865..94081941) | GYPA | Ensembl, NCBI gene |
Variants
By default, variants are sorted chronologically by year of publication, to provide a historical perspective.
Readers can re-sort on any column by clicking on the column header. Click it again to sort in a descending
order. To create a multiple-field sort, hold down Shift while clicking on the second, third etc relevant column
headers.
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 | AVCG Pathogenicity Classification* | Reference Sequence | Chr. | g. or m. | c. or n. | p. | Verbal Description | EVA ID | Year Published | PubMed ID(s) | Acknowledgements |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1887 | Blood group K | GYPA | Ka | delins, small (<=20) | missense | Naturally occurring variant | Not currently evaluated | EquCab3.0 | 2 | NC_009145.3:g.88418148_88418149delinsAT | XM_005607829.3:c.145_146delinsAT | XP_005607886.1:p.(D49I) | rs1146637742, rs1137723782 | 2026 | 41837461 |
* Variant pathogenicity for single-gene diseases as evaluated according to the Animal Variant Classification Guidelines (AVCG) by the Variant Pathogenicity Working Group of the International Society of Animal Genetics (ISAG) Animal Genetic Testing Standardization (AGTS) Standing Committee: P = pathogenic, LP = likely pathogenic, VUS = variant of unknown significance, LB = likely benign, B = benign. For more information (including details on the classification of each variant) see LINKS.
Contact us
If you notice anything missing or in need of change, please contact us at: [email protected].
Cite this entry
Nicholas, F. W., Tammen, I., & Sydney Informatics Hub. (2026). OMIA:000131-9796: Online Mendelian Inheritance in Animals (OMIA) [dataset]. https://omia.org/. https://doi.org/10.25910/2AMR-PV70
References
Note: the references are listed in reverse chronological order (from the most recent year to the earliest year), and alphabetically by first author within a year.
| 2026 | Mackowski, M., Kajdasz, A., Laskowska, K., Cieslak, J. : |
| Evidence that GYPA (glycophorin A) encodes the K blood group system in horses. Anim Genet 57:e70083, 2026. Pubmed reference: 41837461. DOI: 10.1002/age.70083. | |
| 2000 | Sandberg, K., Cothran, E.G. : |
| Blood Groups and Biochemical Polymorphisms. The Genetics of the Horse, edited by Bowling and Ruvinsky. CABI :85–108, 2000. | |
| 1984 | Andersson, L., Sandberg, K. : |
| Genetic linkage in the horse. II. Distribution of male recombination estimates and the influence of age, breed and sex on recombination frequency. Genetics 106:109-22, 1984. Pubmed reference: 6693021. DOI: 10.1093/genetics/106.1.109. | |
| Sandberg, K., Andersson, L. : | |
| Genetic linkage in the horse. I. Linkage relationships among 15 blood marker loci. Hereditas 100:199-208, 1984. Pubmed reference: 6746298. DOI: 10.1111/j.1601-5223.1984.tb00120.x. | |
| 1974 | Sandberg, K. : |
| Linkage between the K blood group locus and the 6-PGD locus in horses. AnimalBlood Groups and Biochemical Genetics 5:137–141, 1974. DOI: 10.1111/j.1365-2052.1974.tb01323.x. |
Edit History
- Created by Imke Tammen2 on 08 Apr 2026
- Changed by Imke Tammen2 on 08 Apr 2026