Two Cases of Chromosome 27 Trisomy in Horses Detected Using Illumina BeadChip Genotyping
Autosomal trisomy, a genetic disorder characterized by the presence of an extra autosome, is a rare but important chromosomal abnormality in horses, often associated with infertility, developmental abnormalities, and reduced life expectancy. This study represents the largest population-level screeni...
Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-06-01
|
| Series: | Animals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-2615/15/13/1842 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850119200371113984 |
|---|---|
| author | Cliona A. Ryan Donagh P. Berry Monika Bugno-Poniewierska Mary-Kate Burke Terje Raudsepp Sonja Egan Jennifer L. Doyle |
| author_facet | Cliona A. Ryan Donagh P. Berry Monika Bugno-Poniewierska Mary-Kate Burke Terje Raudsepp Sonja Egan Jennifer L. Doyle |
| author_sort | Cliona A. Ryan |
| collection | DOAJ |
| description | Autosomal trisomy, a genetic disorder characterized by the presence of an extra autosome, is a rare but important chromosomal abnormality in horses, often associated with infertility, developmental abnormalities, and reduced life expectancy. This study represents the largest population-level screening for autosomal trisomy in horses; the analysis used single nucleotide polymorphism (SNP) panel genotype intensity data from 17,078 horses, 6601 of which were juveniles (i.e., ≤12 months of age) when genotyped. Using methodologies adapted from similar screening studies in cattle, the only aneuploidy detected was trisomy 27 in two juvenile male Irish Sport Horses (ISH) (0.03% prevalence among juveniles or 0.01% prevalence in the overall population). One ISH colt was cytogenetically confirmed and displayed no overt external phenotypic abnormalities, while cytogenetics was not undertaken on the other ISH colt, nor was it phenotypically assessed. Parentage analysis revealed that one ISH colt inherited two different copies of chr27 from the sire, demonstrating heterodisomy, likely due to a nondisjunction event during meiosis I in the sire. The other ISH colt inherited two different copies of chr27 from the dam, also indicating heterodisomy; the dam was 23 years of age when the colt was born. Based on the observed prevalence of autosomal trisomy, it can be estimated that at least 3 foals per 10,000 live births are likely to have autosomal trisomy. Though, given that only 74 (i.e., 0.004%) of horses were genotyped within a month of birth, this is likely an underestimate. The economic consequence of undiagnosed trisomy in high-value breeding horses that are potentially infertile could be substantial. As horse genotyping for parentage verification and discovery is transitioning to medium-density single nucleotide polymorphism panels, routine genomic screening for autosomal aneuploidy could be readily undertaken and potentially should form a standard screening prerequisite along with other genetic defects at horse sales. Currently, thoroughbred horses registered for racing are not genotyped, and only a limited number of sport horse studbooks are using SNP genotyping. This highlights an opportunity for those already genotyping to expand their support for breeders through low-cost, high-value chromosomal screening at the time of registration rather than incurring additional costs over the horse’s life cycle to determine the root cause of certain phenotypes owing to the undiagnosed trisomy. |
| format | Article |
| id | doaj-art-cf83f2e7602d491ca8954fb1874f6638 |
| institution | OA Journals |
| issn | 2076-2615 |
| language | English |
| publishDate | 2025-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Animals |
| spelling | doaj-art-cf83f2e7602d491ca8954fb1874f66382025-08-20T02:35:42ZengMDPI AGAnimals2076-26152025-06-011513184210.3390/ani15131842Two Cases of Chromosome 27 Trisomy in Horses Detected Using Illumina BeadChip GenotypingCliona A. Ryan0Donagh P. Berry1Monika Bugno-Poniewierska2Mary-Kate Burke3Terje Raudsepp4Sonja Egan5Jennifer L. Doyle6Teagasc, Moorepark, Fermoy, P61 P302 Co. Cork, IrelandTeagasc, Moorepark, Fermoy, P61 P302 Co. Cork, IrelandDepartment of Animal Reproduction, Anatomy and Genomics, University of Agriculture in Krakow, Mickiewicza 24/28 Av., 30-059 Kraków, PolandDepartment of Veterinary Medicine, School of Science and Computing, SETU, X91 CF21 Co. Waterford, IrelandDepartment of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX 77840, USAHorse Sport Ireland, Beech House, Millennium Park, Naas, W91 TK7N Co. Kildare, IrelandHorse Sport Ireland, Beech House, Millennium Park, Naas, W91 TK7N Co. Kildare, IrelandAutosomal trisomy, a genetic disorder characterized by the presence of an extra autosome, is a rare but important chromosomal abnormality in horses, often associated with infertility, developmental abnormalities, and reduced life expectancy. This study represents the largest population-level screening for autosomal trisomy in horses; the analysis used single nucleotide polymorphism (SNP) panel genotype intensity data from 17,078 horses, 6601 of which were juveniles (i.e., ≤12 months of age) when genotyped. Using methodologies adapted from similar screening studies in cattle, the only aneuploidy detected was trisomy 27 in two juvenile male Irish Sport Horses (ISH) (0.03% prevalence among juveniles or 0.01% prevalence in the overall population). One ISH colt was cytogenetically confirmed and displayed no overt external phenotypic abnormalities, while cytogenetics was not undertaken on the other ISH colt, nor was it phenotypically assessed. Parentage analysis revealed that one ISH colt inherited two different copies of chr27 from the sire, demonstrating heterodisomy, likely due to a nondisjunction event during meiosis I in the sire. The other ISH colt inherited two different copies of chr27 from the dam, also indicating heterodisomy; the dam was 23 years of age when the colt was born. Based on the observed prevalence of autosomal trisomy, it can be estimated that at least 3 foals per 10,000 live births are likely to have autosomal trisomy. Though, given that only 74 (i.e., 0.004%) of horses were genotyped within a month of birth, this is likely an underestimate. The economic consequence of undiagnosed trisomy in high-value breeding horses that are potentially infertile could be substantial. As horse genotyping for parentage verification and discovery is transitioning to medium-density single nucleotide polymorphism panels, routine genomic screening for autosomal aneuploidy could be readily undertaken and potentially should form a standard screening prerequisite along with other genetic defects at horse sales. Currently, thoroughbred horses registered for racing are not genotyped, and only a limited number of sport horse studbooks are using SNP genotyping. This highlights an opportunity for those already genotyping to expand their support for breeders through low-cost, high-value chromosomal screening at the time of registration rather than incurring additional costs over the horse’s life cycle to determine the root cause of certain phenotypes owing to the undiagnosed trisomy.https://www.mdpi.com/2076-2615/15/13/1842SNPtrisomyaneuploidyinfertilityhorseFISH |
| spellingShingle | Cliona A. Ryan Donagh P. Berry Monika Bugno-Poniewierska Mary-Kate Burke Terje Raudsepp Sonja Egan Jennifer L. Doyle Two Cases of Chromosome 27 Trisomy in Horses Detected Using Illumina BeadChip Genotyping Animals SNP trisomy aneuploidy infertility horse FISH |
| title | Two Cases of Chromosome 27 Trisomy in Horses Detected Using Illumina BeadChip Genotyping |
| title_full | Two Cases of Chromosome 27 Trisomy in Horses Detected Using Illumina BeadChip Genotyping |
| title_fullStr | Two Cases of Chromosome 27 Trisomy in Horses Detected Using Illumina BeadChip Genotyping |
| title_full_unstemmed | Two Cases of Chromosome 27 Trisomy in Horses Detected Using Illumina BeadChip Genotyping |
| title_short | Two Cases of Chromosome 27 Trisomy in Horses Detected Using Illumina BeadChip Genotyping |
| title_sort | two cases of chromosome 27 trisomy in horses detected using illumina beadchip genotyping |
| topic | SNP trisomy aneuploidy infertility horse FISH |
| url | https://www.mdpi.com/2076-2615/15/13/1842 |
| work_keys_str_mv | AT clionaaryan twocasesofchromosome27trisomyinhorsesdetectedusingilluminabeadchipgenotyping AT donaghpberry twocasesofchromosome27trisomyinhorsesdetectedusingilluminabeadchipgenotyping AT monikabugnoponiewierska twocasesofchromosome27trisomyinhorsesdetectedusingilluminabeadchipgenotyping AT marykateburke twocasesofchromosome27trisomyinhorsesdetectedusingilluminabeadchipgenotyping AT terjeraudsepp twocasesofchromosome27trisomyinhorsesdetectedusingilluminabeadchipgenotyping AT sonjaegan twocasesofchromosome27trisomyinhorsesdetectedusingilluminabeadchipgenotyping AT jenniferldoyle twocasesofchromosome27trisomyinhorsesdetectedusingilluminabeadchipgenotyping |