{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T21:05:48Z","timestamp":1782248748396,"version":"3.54.5"},"reference-count":48,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2025,6,22]],"date-time":"2025-06-22T00:00:00Z","timestamp":1750550400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Science Foundation Ireland and the Department of Agriculture, Food and Marine (Dublin, Ireland)","award":["21\/RC\/10303_P2"],"award-info":[{"award-number":["21\/RC\/10303_P2"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>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., \u226412 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\u2019s life cycle to determine the root cause of certain phenotypes owing to the undiagnosed trisomy.<\/jats:p>","DOI":"10.3390\/ani15131842","type":"journal-article","created":{"date-parts":[[2025,6,23]],"date-time":"2025-06-23T03:39:26Z","timestamp":1750649966000},"page":"1842","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Two Cases of Chromosome 27 Trisomy in Horses Detected Using Illumina BeadChip Genotyping"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6708-9669","authenticated-orcid":false,"given":"Cliona A.","family":"Ryan","sequence":"first","affiliation":[{"name":"Teagasc, Moorepark, Fermoy, P61 P302 Co. Cork, Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4349-1447","authenticated-orcid":false,"given":"Donagh P.","family":"Berry","sequence":"additional","affiliation":[{"name":"Teagasc, Moorepark, Fermoy, P61 P302 Co. Cork, Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7537-6641","authenticated-orcid":false,"given":"Monika","family":"Bugno-Poniewierska","sequence":"additional","affiliation":[{"name":"Department of Animal Reproduction, Anatomy and Genomics, University of Agriculture in Krakow, Mickiewicza 24\/28 Av., 30-059 Krak\u00f3w, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-5322-3814","authenticated-orcid":false,"given":"Mary-Kate","family":"Burke","sequence":"additional","affiliation":[{"name":"Department of Veterinary Medicine, School of Science and Computing, SETU, X91 CF21 Co. Waterford, Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2276-475X","authenticated-orcid":false,"given":"Terje","family":"Raudsepp","sequence":"additional","affiliation":[{"name":"Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX 77840, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2503-2298","authenticated-orcid":false,"given":"Sonja","family":"Egan","sequence":"additional","affiliation":[{"name":"Horse Sport Ireland, Beech House, Millennium Park, Naas, W91 TK7N Co. Kildare, Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5247-4660","authenticated-orcid":false,"given":"Jennifer L.","family":"Doyle","sequence":"additional","affiliation":[{"name":"Horse Sport Ireland, Beech House, Millennium Park, Naas, W91 TK7N Co. Kildare, Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Bugno-Poniewierska, M., and Raudsepp, T. (2021). Horse Clinical Cytogenetics: Recurrent Themes and Novel Findings. Animals, 11.","DOI":"10.3390\/ani11030831"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"e2405636121","DOI":"10.1073\/pnas.2405636121","article-title":"Naturally occurring horse model of miscarriage reveals temporal relationship between chromosomal aberration type and point of lethality","volume":"121","author":"Lawson","year":"2024","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"280","DOI":"10.1038\/35066065","article-title":"To err (meiotically) is human: The genesis of human aneuploidy","volume":"2","author":"Hassold","year":"2001","journal-title":"Nat. Rev. Genet."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"737","DOI":"10.1534\/genetics.108.090878","article-title":"Aneuploidy: Cells losing their balance","volume":"179","author":"Torres","year":"2008","journal-title":"Genetics"},{"key":"ref_5","unstructured":"Pai, G.S., Lewandowski, R.C., and Borgaonkar, D.S. (2003). Handbook of Chromosomal Syndromes, Wiley-Liss."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1111\/jbg.12902","article-title":"Prevalence of Autosomal Monosomy and Trisomy Estimated Using Single Nucleotide Polymorphism Genotype Intensity Chip Information in a Large Population of Juvenile Dairy and Beef Cattle","volume":"142","author":"Ryan","year":"2024","journal-title":"J. Anim. Breed. Genet."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1111\/j.2042-3306.1989.tb02092.x","article-title":"Autosomal trisomy in a Standardbred colt","volume":"21","author":"Klunder","year":"1989","journal-title":"Equine Vet. J."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"679","DOI":"10.1139\/g90-101","article-title":"Two autosomal trisomies in the horse: 64,XX,\u221226,+t(26q26q) and 65,XX,+30","volume":"33","author":"Bowling","year":"1990","journal-title":"Genome"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"431","DOI":"10.1016\/j.jevs.2008.06.003","article-title":"Autosomic 27 trisomy in a standardbred colt","volume":"28","author":"Brito","year":"2008","journal-title":"J. Equine Vet. Sci."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1159\/000132448","article-title":"Equine half sibs with an unbalanced X;15 translocation or trisomy 28","volume":"45","author":"Power","year":"1987","journal-title":"Cytogenet. Cell Genet."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"132","DOI":"10.1007\/BF00291532","article-title":"Down\u2019s syndrome in the male. Reproductive pathology and meiotic studies","volume":"63","author":"Johannisson","year":"1983","journal-title":"Hum. Genet."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1024\/0036-7281.149.5.227","article-title":"Karyotype evaluation among young horse populations in Poland","volume":"149","author":"Bugno","year":"2007","journal-title":"Schweiz. Arch. Tierheilkd."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"571","DOI":"10.1111\/jbg.12866","article-title":"Prevalence of sex-chromosome aneuploidy estimated using SNP genotype intensity information in a large population of juvenile dairy and beef cattle","volume":"141","author":"Ryan","year":"2024","journal-title":"J. Anim. Breed. Genet."},{"key":"ref_14","first-page":"1042","article-title":"Characterization of an X-chromosomal non-mosaic monosomy (59, X0) dairy heifer detected using routinely available single nucleotide polymorphism genotype data","volume":"95","author":"Berry","year":"2017","journal-title":"J. Anim. Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2462","DOI":"10.1017\/S1751731118000204","article-title":"Aneuploidy in dizygotic twin sheep detected using genome-wide single nucleotide polymorphism data from two commonly used commercial vendors","volume":"12","author":"Berry","year":"2018","journal-title":"Animal"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2017","DOI":"10.1016\/j.fertnstert.2010.01.052","article-title":"Accurate single cell 24 chromosome aneuploidy screening using whole genome amplification and single nucleotide polymorphism microarrays","volume":"94","author":"Treff","year":"2010","journal-title":"Fertil. Steril."},{"key":"ref_17","unstructured":"Tuke, M.A., Ruth, K.S., Wood, A.R., Beaumont, R.N., Tyrrell, J., Jones, S.E., Yaghootkar, H., Turner, C.L., Donohoe, M.E., and Brooke, A.M. (2017). Phenotypes associated with female X chromosome aneuploidy in UK Biobank: An unselected, adult, population-based cohort. bioRxiv."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1016\/j.gdata.2014.05.007","article-title":"Using SNP array to identify aneuploidy and segmental imbalance in translocation carriers","volume":"2","author":"Xiong","year":"2014","journal-title":"Genom. Data"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"304","DOI":"10.1111\/jbg.12760","article-title":"Classifying aneuploidy in genotype intensity data using deep learning","volume":"140","author":"Bouwman","year":"2023","journal-title":"J. Anim. Breed. Genet."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1136","DOI":"10.1101\/gr.5402306","article-title":"High-resolution genomic profiling of chromosomal aberrations using Infinium whole-genome genotyping","volume":"16","author":"Peiffer","year":"2006","journal-title":"Genome Res."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Staaf, J., Vallon-Christersson, J., Lindgren, D., Juliusson, G., Rosenquist, R., H\u00f6glund, M., Borg, \u00c5., and Ringn\u00e9r, M. (2008). Normalization of Illumina Infinium whole-genome SNP data improves copy number estimates and allelic intensity ratios. BMC Bioinform., 9.","DOI":"10.1186\/1471-2105-9-409"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Hashem, E.M., Mabrouk, M.S., and Eldeib, A.M. (2016). Novel altered region for biomarker discovery in hepatocellular carcinoma (HCC) using whole genome SNP array. Int. J. Adv. Comput. Sci. Appl., 7.","DOI":"10.14569\/IJACSA.2016.070401"},{"key":"ref_23","unstructured":"Wang, H., and Federoff, S. (1974). Trypsin technique to reveal G-bands. Tissue Culture Methods and Applications, Academic Press."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"283","DOI":"10.1159\/000056917","article-title":"International System for Chromosome Nomenclature of Domestic Bovids (ISCNDB 2000)","volume":"92","author":"Cribiu","year":"2001","journal-title":"Cytogenet. Cell Genet."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"786","DOI":"10.1111\/evj.14097","article-title":"Molecular cytogenetic screening of sex chromosome abnormalities in young horse populations","volume":"56","author":"Jankowska","year":"2024","journal-title":"Equine Vet. J."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1007\/978-1-59745-581-7_3","article-title":"FISH for mapping single copy genes","volume":"422","author":"Raudsepp","year":"2008","journal-title":"Phylogenomics"},{"key":"ref_27","first-page":"94","article-title":"Exclusion of chromosomal mosaicism: Tables of 90%, 95% and 99% confidence limits and comments on use","volume":"29","author":"Hook","year":"1977","journal-title":"Am. J. Hum. Genet."},{"key":"ref_28","unstructured":"Weatherbys (2023). Weatherbys Fact Book, Weatherbys GSB."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"100996","DOI":"10.1016\/j.animal.2023.100996","article-title":"Animal board invited review: Practical applications of genomic information in livestock","volume":"17","author":"Berry","year":"2023","journal-title":"Animal"},{"key":"ref_30","unstructured":"Swaiman, K.F., Ashwal, S., Ferriero, D.M., Schor, N.F., Finkel, R.S., Gropman, A.L., Pearl, P.L., and Shevell, M.I. (2017). 35-Chromosomes and Chromosomal Abnormalities. Swaiman\u2019s Pediatric Neurology, Elsevier. [6th ed.]."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Shilton, C.A., Kahler, A., Davis, B.W., Crabtree, J.R., Crowhurst, J., McGladdery, A.J., Wathes, D.C., Raudsepp, T., and de Mestre, A.M. (2020). Whole genome analysis reveals aneuploidies in early pregnancy loss in the horse. Sci. Rep., 10.","DOI":"10.1038\/s41598-020-69967-z"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Silvestri, G., Canedo-Ribeiro, C., Serrano-Albal, M., Labrecque, R., Blondin, P., Larmer, S.G., Marras, G., Tutt, D.A.R., Handyside, A.H., and Farr\u00e9, M. (2021). Preimplantation Genetic Testing for Aneuploidy Improves Live Birth Rates with In Vitro Produced Bovine Embryos: A Blind Retrospective Study. Cells, 10.","DOI":"10.3390\/cells10092284"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"R203","DOI":"10.1093\/hmg\/ddm243","article-title":"The origin of human aneuploidy: Where we have been, where we are going","volume":"16","author":"Hassold","year":"2007","journal-title":"Hum. Mol. Genet."},{"key":"ref_34","first-page":"1","article-title":"From cytogenetics to cytogenomics: A new era in the diagnosis of chromosomal abnormalities in domestic animals","volume":"54","author":"Switonski","year":"2025","journal-title":"J. Appl. Genet."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Ghosh, S., Kj\u00f6llerstr\u00f6m, J., Metcalfe, L., Reed, S., Juras, R., and Raudsepp, T. (2022). The Second Case of Non-Mosaic Trisomy of Chromosome 26 with Homologous Fusion 26q;26q in the Horse. Animals, 12.","DOI":"10.3390\/ani12070803"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1111\/j.2042-3306.1999.tb03796.x","article-title":"Autosomal trisomy in a Thoroughbred colt: 65,XY,+31","volume":"31","author":"Lear","year":"1999","journal-title":"Equine Vet. J."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"60","DOI":"10.1111\/j.2042-3306.1997.tb01638.x","article-title":"Arthrogryposis in the foal and its possible relation to autosomal trisomy","volume":"29","author":"Buoen","year":"1997","journal-title":"Equine Vet. J."},{"key":"ref_38","unstructured":"Zhang, T., Bellamy, J., Buwn, L., Weber, A., and Ruth, G. (1992, January 18\u201321). Autosomal trisomy in a foal with contracted tendon syndrome. Proceedings of the 10th European Colloqium on Cytogenetics of Domestic Animals, Utrecht, The Netherlands."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"22220","DOI":"10.18632\/aging.104159","article-title":"The horse as a natural model to study reproductive aging-induced aneuploidy and weakened centromeric cohesion in oocytes","volume":"12","author":"Rizzo","year":"2020","journal-title":"Aging"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Hole\u010dkov\u00e1, B., Schwarzbacherov\u00e1, V., Gald\u00edkov\u00e1, M., Koleni\u010dov\u00e1, S., Halu\u0161kov\u00e1, J., Stani\u010dov\u00e1, J., Verebov\u00e1, V., and Jutkov\u00e1, A. (2021). Chromosomal Aberrations in Cattle. Genes, 12.","DOI":"10.3390\/genes12091330"},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Gersen, S.L., and Keagle, M.B. (2013). The Principles of Clinical Cytogenetics, Springer Nature.","DOI":"10.1007\/978-1-4419-1688-4"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"e2209139119","DOI":"10.1073\/pnas.2209139119","article-title":"Evolution of the ancestral mammalian karyotype and syntenic regions","volume":"119","author":"Damas","year":"2022","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1136\/vr.146.6.163","article-title":"Trisomy 26 mosaicism in a sterile Holstein-Friesian heifer","volume":"146","author":"Ducos","year":"2000","journal-title":"Vet. Rec."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"576","DOI":"10.1111\/j.1439-0442.1993.tb00669.x","article-title":"Trisomy 22 in a calf","volume":"40","author":"Agerholm","year":"1993","journal-title":"J. Vet. Med. Ser. A"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1186\/BF03548250","article-title":"Autosomal trisomy in a heifer","volume":"28","author":"Alitalo","year":"1987","journal-title":"Acta Vet. Scand."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"252","DOI":"10.1007\/s00335-013-9450-6","article-title":"Detection of two equine trisomies using SNP-CGH","volume":"24","author":"Holl","year":"2013","journal-title":"Mamm. Genome"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1159\/000056844","article-title":"Nondisjunction in trisomy 21: Origin and mechanisms","volume":"91","author":"Petersen","year":"2000","journal-title":"Cytogenet. Cell Genet."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"569","DOI":"10.1111\/age.12857","article-title":"Ten years of the horse reference genome: Insights into equine biology, domestication and population dynamics in the post-genome era","volume":"50","author":"Raudsepp","year":"2019","journal-title":"Anim. Genet."}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/15\/13\/1842\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:56:31Z","timestamp":1760032591000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/15\/13\/1842"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,22]]},"references-count":48,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2025,7]]}},"alternative-id":["ani15131842"],"URL":"https:\/\/doi.org\/10.3390\/ani15131842","relation":{},"ISSN":["2076-2615"],"issn-type":[{"value":"2076-2615","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,6,22]]}}}