OMIA:001230-9796 : XY sex reversal, SRY-related in Equus caballus (horse)

In other species: pig , Western roe deer , taurine cattle , sheep , rabbit

Categories: Reproductive system phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 400044 (trait) , 480000 (gene)

Links to relevant human diseases in MONDO:

Mendelian trait/disorder: yes

Mode of inheritance: Y-linked

Considered a defect: yes

Key variant known: yes

Year key variant first reported: 1995

Cross-species summary: This is type of XY difference of sexual development (XY DSD) due to variation in the SRY gene. In humans called 46,XY sex reversal 1. Renamed in OMIA from "Ovotesticular DSD (Disorder of Sexual evelopment)" [29/09/2023]. Previously this phene ID was named in OMIA 'Sex reversal: XY female, SRY-negative'

Molecular basis: By cloning and sequencing a very likely comparative candidate gene (based on the homologous disorder in other species), Pailhoux et al. (1995) showed that "at least the DNA-binding domain of the SRY gene was deleted from the Y chromosome of the XY mare". Raudsepp et al. (2010) reported molecular heterogeneity in 13 cases of Y-linked XY sex reversal, all of which included deletion of the SRY gene: "the smallest deletions spanned about 21 kb, while the largest involved the entire euchromatic region".

Breed: American Trotter (Horse) (VBO_0000899).
Breeds in which the phene has been documented. (If a likely causal variant has been documented for the phene, see the variant table breeds in which the variant has been reported).

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
SRY sex determining region Y Equus caballus - no genomic information (-..-) SRY Homologene, Ensembl , NCBI gene


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 Type of Variant Source of Genetic Variant Reference Sequence Chr. g. or m. c. or n. p. Verbal Description EVA ID Year Published PubMed ID(s) Acknowledgements
659 American Trotter (Horse) XY sex reversal SRY deletion, gross (>20) Naturally occurring variant Y "at least the DNA-binding domain of the SRY gene was deleted from the Y chromosome of the XY mare" 1995 7558880

Cite this entry

Nicholas, F. W., Tammen, I., & Sydney Informatics Hub. (2024). OMIA:001230-9796: Online Mendelian Inheritance in Animals (OMIA) [dataset].


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.

2024 Bugno-Poniewierska, M., Jankowska, M., Raudsepp, T., Kowalska, K., Pawlina-Tyszko, K., Szmatola, T. :
Molecular cytogenetic screening of sex chromosome abnormalities in young horse populations. Equine Vet J 56:786-795, 2024. Pubmed reference: 38785417. DOI: 10.1111/evj.14097.
2022 Castaneda, C., Radović, L., Felkel, S., Juras, R., Davis, B.W., Cothran, E.G., Wallner, B., Raudsepp, T. :
Copy number variation of horse Y chromosome genes in normal equine populations and in horses with abnormal sex development and subfertility: relationship of copy number variations with Y haplogroups. G3 (Bethesda) 12:jkac278, 2022. Pubmed reference: 36227030. DOI: 10.1093/g3journal/jkac278.
2010 Raudsepp, T., Durkin, K., Lear, T.L., Das, P.J., Avila, F., Kachroo, P., Chowdhary, B.P. :
Molecular heterogeneity of XY sex reversal in horses. Anim Genet 41 Suppl 2:41-52, 2010. Pubmed reference: 21070275. DOI: 10.1111/j.1365-2052.2010.02101.x.
2003 Bugno, M., Klukowska, J., Slota, E., Tischner, M., Switonski, M. :
A sporadic case of the sex-reversed mare (64,XY; SRY-negative): molecular and cytogenetic studies of the Y chromosome Theriogenology 59:1597-603, 2003. Pubmed reference: 12559464.
1999 Abe, S., Miyake, Y.I., Kageyama, S.I., Watanabe, G., Taya, K., Kawakura, K. :
Deletion of the Sry region on the Y chromosome detected in a case of equine gonadal hypoplasia (XY female) with abnormal hormonal profiles. Equine Vet J 31:336-8, 1999. Pubmed reference: 10454094.
Mäkinen, A., Hasegawa, T., Mäkilä, M., Katila, T. :
Infertility in two mares with XY and XXX sex chromosomes. Equine Vet J 31:346-9, 1999. Pubmed reference: 10454097. DOI: 10.1111/j.2042-3306.1999.tb03829.x.
1995 Pailhoux, E., Cribiu, E.P., Parma, P., Cotinot, C. :
Molecular analysis of an XY mare with gonadal dysgenesis Hereditas 122:109-112, 1995. Pubmed reference: 7558880.

Edit History

  • Created by Frank Nicholas on 12 Sep 2005
  • Changed by Frank Nicholas on 11 Sep 2011
  • Changed by Frank Nicholas on 08 Oct 2011
  • Changed by Frank Nicholas on 09 Dec 2011
  • Changed by Frank Nicholas on 31 Aug 2012
  • Changed by Frank Nicholas on 31 Dec 2015
  • Changed by Frank Nicholas on 05 Mar 2020
  • Changed by Imke Tammen2 on 01 Oct 2023
  • Changed by Imke Tammen2 on 03 Jun 2024