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Durward-Akhurst SA, Marlowe JL, Schaefer RJ, Springer K, Grantham B, Carey WK, Bellone RR, Mickelson JR, McCue ME. Predicted genetic burden and frequency of phenotype-associated variants in the horse. Sci Rep 2024; 14:8396. [PMID: 38600096 PMCID: PMC11006912 DOI: 10.1038/s41598-024-57872-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 03/22/2024] [Indexed: 04/12/2024] Open
Abstract
Disease-causing variants have been identified for less than 20% of suspected equine genetic diseases. Whole genome sequencing (WGS) allows rapid identification of rare disease causal variants. However, interpreting the clinical variant consequence is confounded by the number of predicted deleterious variants that healthy individuals carry (predicted genetic burden). Estimation of the predicted genetic burden and baseline frequencies of known deleterious or phenotype associated variants within and across the major horse breeds have not been performed. We used WGS of 605 horses across 48 breeds to identify 32,818,945 variants, demonstrate a high predicted genetic burden (median 730 variants/horse, interquartile range: 613-829), show breed differences in predicted genetic burden across 12 target breeds, and estimate the high frequencies of some previously reported disease variants. This large-scale variant catalog for a major and highly athletic domestic animal species will enhance its ability to serve as a model for human phenotypes and improves our ability to discover the bases for important equine phenotypes.
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Affiliation(s)
- S A Durward-Akhurst
- Department of Veterinary Clinical Sciences, University of Minnesota, C339 VMC, 1353 Boyd Avenue, St. Paul, MN, 55108, USA.
| | - J L Marlowe
- Department of Veterinary Clinical Sciences, University of Minnesota, C339 VMC, 1353 Boyd Avenue, St. Paul, MN, 55108, USA
| | - R J Schaefer
- Department of Veterinary Population Medicine, University of Minnesota, 225 VMC, 1365 Gortner Avenue, St. Paul, MN, 55108, USA
| | - K Springer
- Department of Veterinary Population Medicine, University of Minnesota, 225 VMC, 1365 Gortner Avenue, St. Paul, MN, 55108, USA
| | - B Grantham
- Interval Bio LLC, 408 Stierline Road, Mountain View, CA, 94043, USA
| | - W K Carey
- Interval Bio LLC, 408 Stierline Road, Mountain View, CA, 94043, USA
| | - R R Bellone
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA
- Population Health and Reproduction and Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - J R Mickelson
- Department of Veterinary and Biomedical Sciences, University of Minnesota, 295F Animal Science Veterinary Medicine Building, 1988 Fitch Avenue, St. Paul, MN, 55108, USA
| | - M E McCue
- Department of Veterinary Population Medicine, University of Minnesota, 225 VMC, 1365 Gortner Avenue, St. Paul, MN, 55108, USA
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De Coster T, Zhao Y, Tšuiko O, Demyda-Peyrás S, Van Soom A, Vermeesch JR, Smits K. Genome-wide equine preimplantation genetic testing enabled by simultaneous haplotyping and copy number detection. Sci Rep 2024; 14:2003. [PMID: 38263320 PMCID: PMC10805710 DOI: 10.1038/s41598-023-48103-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 11/22/2023] [Indexed: 01/25/2024] Open
Abstract
In different species, embryonic aneuploidies and genome-wide errors are a major cause of developmental failure. The increasing number of equine embryos being produced worldwide provides the opportunity to characterize and rank or select embryos based on their genetic profile prior to transfer. Here, we explored the possibility of generic, genome-wide preimplantation genetic testing concurrently for aneuploidies (PGT-A) and monogenic (PGT-M) traits and diseases in the horse, meanwhile assessing the incidence and spectrum of chromosomal and genome-wide errors in in vitro-produced equine embryos. To this end, over 70,000 single nucleotide polymorphism (SNP) positions were genotyped in 14 trophectoderm biopsies and corresponding biopsied blastocysts, and in 26 individual blastomeres from six arrested cleavage-stage embryos. Subsequently, concurrent genome-wide copy number detection and haplotyping by haplarithmisis was performed and the presence of aneuploidies and genome-wide errors and the inherited parental haplotypes for four common disease-associated genes with high carrier frequency in different horse breeds (GBE1, PLOD1, B3GALNT2, MUTYH), and for one color coat-associated gene (STX17) were compared in biopsy-blastocyst combinations. The euploid (n = 12) or fully aneuploid (n = 2) state and the inherited parental haplotypes for 42/45 loci of interest of the biopsied blastocysts were predicted by the biopsy samples in all successfully analyzed biopsy-blastocyst combinations (n = 9). Two biopsies showed a loss of maternal chromosome 28 and 31, respectively, which were confirmed in the corresponding blastocysts. In one of those biopsies, additional complex aneuploidies not present in the blastocyst were found. Five out of six arrested embryos contained chromosomal and/or genome-wide errors in most of their blastomeres, demonstrating their contribution to equine embryonic arrest in vitro. The application of the described PGT strategy would allow to select equine embryos devoid of genetic errors and pathogenetic variants, and with the variants of interest, which will improve foaling rate and horse quality. We believe this approach will be a gamechanger in horse breeding.
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Affiliation(s)
- T De Coster
- Department of Internal Medicine, Reproduction and Population Medicine, Ghent University, Merelbeke, Belgium.
- Department of Human Genetics, KU Leuven, Leuven, Belgium.
| | - Y Zhao
- Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - O Tšuiko
- Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - S Demyda-Peyrás
- Department of Genetics, University of Córdoba, Córdoba, Spain
- Department of Animal Production, Veterinary School, National University of La Plata, La Plata, Argentina
| | - A Van Soom
- Department of Internal Medicine, Reproduction and Population Medicine, Ghent University, Merelbeke, Belgium
| | - J R Vermeesch
- Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - K Smits
- Department of Internal Medicine, Reproduction and Population Medicine, Ghent University, Merelbeke, Belgium.
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McElroy A, Gray‐Edwards H, Coghill LM, Lyons LA. Precision medicine using whole genome sequencing in a cat identifies a novel COL5A1 variant for classical Ehlers-Danlos syndrome. J Vet Intern Med 2023; 37:1716-1724. [PMID: 37594181 PMCID: PMC10473008 DOI: 10.1111/jvim.16805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 06/28/2023] [Indexed: 08/19/2023] Open
Abstract
BACKGROUND Ehlers-Danlos syndromes (EDS) are a heterogeneous group of heritable connective tissue disorders occurring in both human and veterinary patients. The genetics of these disorders are poorly described in small animal patients. HYPOTHESIS/OBJECTIVES Define the clinical manifestations and genetic cause of a suspected form of EDS in a cat. ANIMALS A 14-week-old male domestic medium hair cat was presented with skin hyperextensibility and fragility. The classic tragic facial expression was observed as well as chronic pruritus and mild hyperesthesia. METHODS Blood samples and a skin biopsy sample were collected from the affected cat. Clinical examinations, histology, electron microscopy and whole genome sequencing were conducted to characterize the clinical presentation and identify possible pathogenic DNA variants to support a diagnosis. Criteria defining variant pathogenicity were examined including human disease variant databases. RESULTS Histology showed sparse, disorganized collagen and an increase in cutaneous mast cells. Electron microscopy identified ultrastructural defects commonly seen in collagen type V alpha 1 chain (COL5A1) variants including flower-like collagen fibrils in cross-section. Whole genome sequencing and comparison with 413 cats in the 99 Lives Cat Genome Sequencing Consortium database identified a novel splice acceptor site variant at exon 4 in COL5A1 (c.501-2A>C). CONCLUSIONS AND CLINICAL IMPORTANCE Our report broadens the current understanding of EDS in veterinary patients and supports the use of precision medicine techniques in clinical veterinary practice. The classification of variants for pathogenicity should be considered in companion animals.
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Affiliation(s)
- Abigail McElroy
- Horae Gene Therapy CenterUniversity of Massachusetts Chan Medical SchoolWorcesterMassachusettsUSA
| | - Heather Gray‐Edwards
- Horae Gene Therapy CenterUniversity of Massachusetts Chan Medical SchoolWorcesterMassachusettsUSA
- Department of RadiologyUniversity of Massachusetts Chan Medical SchoolWorcesterMassachusettsUSA
| | - Lyndon M. Coghill
- Department of Veterinary Pathobiology, College of Veterinary MedicineUniversity of MissouriColumbiaMissouriUSA
| | - Leslie A. Lyons
- Department of Veterinary Medicine & Surgery, College of Veterinary MedicineUniversity of MissouriColumbiaMissouriUSA
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Elcombe ME, Bellone RR, Magdesian KG, Finno CJ. Prevalence of the RAPGEF5 c.2624C>A and PLOD1 c.2032G>A variants associated with equine familial isolated hypoparathyroidism and fragile foal syndrome in the US Thoroughbred population (1988-2019). Equine Vet J 2023; 55:666-671. [PMID: 36199159 PMCID: PMC10073348 DOI: 10.1111/evj.13883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 09/23/2022] [Indexed: 11/26/2022]
Abstract
BACKGROUND Equine familial isolated hypoparathyroidism (EFIH) and fragile foal syndrome (FFS) are both fatal recessive conditions reported in Thoroughbred foals. The causal variants for EFIH (RAPGEF5 c.2624C>A; EquCab3.0. chr4: g.54108297G>T) and FFS (PLOD1 c.2032G>A; EquCab3.0, chr2: g.39927817) were recently reported. Prevalence assessment for these variants in a large cohort of samples is needed to provide evidence-based recommendations for genetic testing. OBJECTIVES To estimate the frequency of the EFIH and FFS variant alleles in the United States Thoroughbred population between 1988 and 2019, and determine whether these are recent mutations or are increasing in frequency due to current breeding practices. STUDY DESIGN Population allele frequency study. METHODS Genomic DNA from hair and serum samples were genotyped for the EFIH and FFS. Allele frequencies between cohorts, based on year of birth (1988-2000, n = 728) and (2001-2019, n = 1059), as well as across the seven geographical regions of the United States were compared by Fisher's Exact tests. RESULTS EFIH and FFS allele frequencies were not significantly different between the two time points studied (0.008 and 0.004, respectively, in the older cohorts and 0.008 and 0.009 in most recent years). No EFIH or FFS homozygotes were detected. A sample from 1992 was identified as a carrier for EFIH and one from 1993 a carrier for FFS. Non-significant changes in geographical distribution of carriers for both traits were observed. MAIN LIMITATIONS The earliest samples available for study were from foals born in 1988. CONCLUSIONS The EFIH and FFS variants are present at low frequency in the United States Thoroughbred population but are not recent mutations. There is no evidence to support changes in allele frequency over time. However, given the closed studbook and breeding practices, continued monitoring of breed allele frequencies and genetic testing is recommended to avoid the mating of carriers and production of affected foals.
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Affiliation(s)
- Megan E. Elcombe
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
| | - Rebecca R. Bellone
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
| | - K. Gary Magdesian
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
| | - Carrie J. Finno
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
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Shilton CA, Kahler A, Roach JM, Raudsepp T, de Mestre AM. Lethal variants of equine pregnancy: is it the placenta or foetus leading the conceptus in the wrong direction? Reprod Fertil Dev 2022; 35:51-69. [PMID: 36592981 DOI: 10.1071/rd22239] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Embryonic and foetal loss remain one of the greatest challenges in equine reproductive health with 5-10% of established day 15 pregnancies and a further 5-10% of day 70 pregnancies failing to produce a viable foal. The underlying reason for these losses is variable but ultimately most cases will be attributed to pathologies of the environment of the developing embryo and later foetus, or a defect intrinsic to the embryo itself that leads to lethality at any stage of gestation right up to birth. Historically, much research has focused on the maternal endometrium, endocrine and immune responses in pregnancy and pregnancy loss, as well as infectious agents such as pathogens, and until recently very little was known about the both small and large genetic variants associated with reduced foetal viability in the horse. In this review, we first introduce key aspects of equine placental and foetal development. We then discuss incidence, risk factors and causes of pregnancy loss, with the latter focusing on genetic variants described to date that can impact equine foetal viability.
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Affiliation(s)
- Charlotte A Shilton
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, Hawkshead Lane, Herts, AL9 7TA, UK
| | - Anne Kahler
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, Hawkshead Lane, Herts, AL9 7TA, UK
| | - Jessica M Roach
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, Hawkshead Lane, Herts, AL9 7TA, UK
| | - Terje Raudsepp
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX 77843-4458, USA
| | - Amanda M de Mestre
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, Hawkshead Lane, Herts, AL9 7TA, UK
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Grillos AS, Roach JM, de Mestre AM, Foote AK, Kinglsey NB, Mienaltowski MJ, Bellone RR. First reported case of fragile foal syndrome type 1 in the Thoroughbred caused by PLOD1 c.2032G>A. Equine Vet J 2022; 54:1086-1093. [PMID: 34939209 PMCID: PMC9213567 DOI: 10.1111/evj.13547] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 11/18/2021] [Accepted: 11/30/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Warmblood Fragile Foal Syndrome Type 1 (WFFS) is an autosomal recessive disorder reported previously only in warmbloods and thought to be caused by a variant in the gene procollagen-lysine,2-oxoglutarate 5-dioxygenase 1 (PLOD1, c.2032G>A, p.Gly678Arg). Given the presentation of this Thoroughbred case, we hypothesised that a similar genetic mechanism caused this phenotype. OBJECTIVES To describe the pathological and genetic findings on a foal presenting to a veterinary practice in the UK with skin lesions similar to other Ehlers-Danlos Syndromes, including those documented for warmbloods with WFFS. STUDY DESIGN A single case report describing a genetic investigation. METHODS A Thoroughbred foal presenting as dystocia was euthanised for multiple skin lesions and developmental abnormalities. DNA extracted from the foal was tested for the PLOD1 variant (c.2032G>A, p.Gly678Arg) using the commercially available assay. To confirm causality and further interrogate potential novel causes of Ehlers-Danlos Syndrome, 1799 functional candidate genes, including PLOD1, were analysed using whole genome sequencing data generated from DNA extracted from the foal's muscle. These data were compared to 34 control samples from at least 11 other breeds. Variants were prioritised for further evaluation based on predicted impact on protein function. RESULTS Post-mortem evaluation concluded that this foal suffered from a condition of collagen dysplasia. The foal was homozygous for the c.2032G>A PLOD1 variant. Only two other missense variants identified from whole genome sequencing data were also computationally predicted to be deleterious to protein function, (NPHP3 c.1253T>C, p.Leu418Pro, EPDR1 c.154G>C, p.Glu52Gln). Neither of these genes have been linked to similar phenotypes, or Ehlers-Danlos Syndrome in humans or other species and thus further investigation of these variants as the cause of EDS was not warranted. MAIN LIMITATIONS This study is a single case report in the Thoroughbred with no additional cases from this breed yet identified to replicate this finding. CONCLUSIONS Given the clinical presentation similar to WFFS, homozygosity for the PLOD1 variant, and absence of another more plausible causal variant from the WGS experiment, we conclude that PLOD1 c.2032G>A is the likely cause of this foal's condition. This is the first documented evidence of fragile foal syndrome caused by the PLOD1 variant in a breed outside of warmbloods, the Thoroughbred. We therefore recommend a change in the name of this disorder to fragile foal syndrome type 1 (FFS) and utilisation of genetic testing in Thoroughbreds to avoid producing affected foals.
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Affiliation(s)
- Alexandra S Grillos
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
| | - Jessica M Roach
- Equine Pregnancy Laboratory, Comparative Biomedical Sciences, Royal Veterinary College, Hertfordshire, UK
| | - Amanda M de Mestre
- Equine Pregnancy Laboratory, Comparative Biomedical Sciences, Royal Veterinary College, Hertfordshire, UK
| | | | - Nicole B Kinglsey
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
| | - Michael J Mienaltowski
- Department of Animal Science, College of Agricultural and Environmental Sciences, University of California-Davis, Davis, California, USA
| | - Rebecca R Bellone
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
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Roach JM, Arango-Sabogal JC, Smith KC, Foote AK, Verheyen KL, de Mestre AM. Multivariable analysis to determine risk factors associated with abortion in mares. REPRODUCTION AND FERTILITY 2022; 3:RAF-22-0087. [PMID: 36374277 PMCID: PMC9782406 DOI: 10.1530/raf-22-0087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 11/14/2022] [Indexed: 11/16/2022] Open
Abstract
Risk factors associated with equine reproductive efficiency have been identified along with those associated specifically with early pregnancy loss (EPL). In contrast, no studies have reported risk factors associated with abortion (loss between day 70 and 300 post-cover). Given the causes of abortion differ to those of EPL, likely too will the risk factors. A retrospective cohort study was carried out to identify risk factors associated with abortion in UK and Irish based Thoroughbreds, collecting data on 20 exposure variables over a five-year period. A generalized linear mixed model was utilized to evaluate the associations between exposure variables and abortion, with clustering of observations accounted for at the mare and farm level. Variables with a likelihood ratio test (LRT) p value <0.2 were entered into the model in a forward stepwise approach. Pregnancy outcome was available on 4,439 pregnancies from 2,510 mares. Having had two or more prior abortions (odds ratio (OR) 7.91, 95% confidence interval (CI) 2.86, 21.88), conceiving on the second or subsequent covered estrous cycle (OR 1.84, 95% CI 1.22, 2.78) and conceiving multiple conceptuses (OR 1.68, 95% CI 1.02, 2.76) were associated with an increased risk of abortion compared to null parous, first estrous cycle covers and singleton conceptions respectively. Increasing paternal age (OR 0.95, 95% CI 0.90, 0.99) was associated with a decreasing risk of abortion. Mare and farm variance were not significant in the final model, LRT p=0.43. These findings provide evidence-based data to inform Thoroughbred breeding management practices to help mitigate abortion risk.
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Affiliation(s)
- J M Roach
- Comparative Biomedical Sciences, Royal Veterinary College, Hawkshead Lane, Hatfield, UK
| | - J C Arango-Sabogal
- Pathobiology and Population Sciences, Royal Veterinary College, Hawkshead Lane, Hatfield, UK
| | - K C Smith
- Pathobiology and Population Sciences, Royal Veterinary College, Hawkshead Lane, Hatfield, UK
| | - A K Foote
- Rossdales Laboratories, Newmarket, UK
| | - K L Verheyen
- Pathobiology and Population Sciences, Royal Veterinary College, Hawkshead Lane, Hatfield, UK
| | - A M de Mestre
- Comparative Biomedical Sciences, Royal Veterinary College, Hawkshead Lane, Hatfield, UK
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Wobbe M, Reinhardt F, Reents R, Tetens J, Stock KF. Quantifying the effect of Warmblood Fragile Foal Syndrome on foaling rates in the German riding horse population. PLoS One 2022; 17:e0267975. [PMID: 35901076 PMCID: PMC9333276 DOI: 10.1371/journal.pone.0267975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 04/19/2022] [Indexed: 11/19/2022] Open
Abstract
Awareness of breeders of Warmblood Fragile Foal Syndrome (WFFS) increased after a widely discussed case in the USA in 2018. The hereditary connective tissue disorder, first described by a US research group in 2011 and for which a commercial genetic test exists since 2013, is caused by a point mutation in the PLOD1 gene, inherited autosomal recessively. Extension of molecular genetic testing and reporting of test results of organized horse breeders to their studbooks implies new opportunities for analyses. In Germany, data are centrally accessible through the integrated equine data base allowing comprehensive and population-wide investigation of the role of WFFS. The objective of this study was statistical testing for associations between WFFS and reproductive performance of German riding horses and quantifying possible differences between WFFS carriers and non-carriers, also in respect of performance traits. For this purpose, covering data from 2008 to 2020 were provided by ten German studbooks, so almost 400,000 coverings and resulting foaling rates were available for multiple analyses of variance with general and mixed linear models using procedures GLM, MIXED and HPMIXED of SAS software (version 9.2). Published breeding values of stallions were used for respective comparisons of riding horse performance. Assuming a WFFS carrier frequency of 9.5–15.0% in Warmblood horses, Hardy Weinberg principle implied an expected difference of 2.4–3.7% in the foaling rates of carrier and non-carrier stallions. Our results provided statistical evidence of detrimental effects of WFFS on the reproductive performance of Warmblood horses with about 2.7% lower average foaling rate in carriers of the mutant allele than in WFFS free sires, if mated to an average mare population. Indications of favorable dressage performance of WFFS carriers were found. Reported WFFS cases indicate only the tip of the iceberg and assessing the impact of WFFS on reproduction requires consideration of premature foal losses.
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Affiliation(s)
- Mirell Wobbe
- Genetic Evaluation Division, IT Solutions for Animal Production (vit), Verden, Germany
- Institute for Animal Breeding and Genetics, University of Veterinary Medicine Hannover (Foundation), Hanover, Germany
- * E-mail:
| | - Friedrich Reinhardt
- Genetic Evaluation Division, IT Solutions for Animal Production (vit), Verden, Germany
| | - Reinhard Reents
- Genetic Evaluation Division, IT Solutions for Animal Production (vit), Verden, Germany
| | - Jens Tetens
- Department of Animal Sciences, University of Goettingen, Goettingen, Germany
- Center for Integrated Breeding Research (CiBreed), University of Goettingen, Goettingen, Germany
| | - Kathrin F. Stock
- Genetic Evaluation Division, IT Solutions for Animal Production (vit), Verden, Germany
- Institute for Animal Breeding and Genetics, University of Veterinary Medicine Hannover (Foundation), Hanover, Germany
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Ablondi M, Johnsson M, Eriksson S, Sabbioni A, Viklund ÅG, Mikko S. Performance of Swedish Warmblood fragile foal syndrome carriers and breeding prospects. Genet Sel Evol 2022; 54:4. [PMID: 35062868 PMCID: PMC8783495 DOI: 10.1186/s12711-021-00693-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 12/21/2021] [Indexed: 11/30/2022] Open
Abstract
Background Warmblood fragile foal syndrome (WFFS) is a monogenetic defect caused by a recessive lethal missense point mutation in the procollagen‐lysine, 2‐oxoglutarate 5‐dioxygenase 1 gene (PLOD1, c.2032G>A). The majority of homozygous WFFS horses are aborted during gestation. Clinical signs of affected horses include fragile skin, skin and mucosa lacerations, hyperextension of the articulations, and hematomas. In spite of its harmful effect, a relatively high frequency of WFFS carriers has been found in Warmblood horses, suggesting a heterozygote advantage. Thus, in this study our aims were to: (1) estimate the frequency of WFFS carriers in the Swedish Warmblood breed (SWB), (2) estimate the effect of WFFS carrier genotype on performance traits in two SWB subpopulations bred for different disciplines, and (3) simulate the potential effects of balancing selection and different selection strategies on the frequency of carriers. Methods In total, 2288 SWB sport horses born between 1971 and 2020 were tested for the WFFS mutation and had estimated breeding values (EBV) for ten traditional evaluating and 50 linear descriptive traits. Results The frequency of WFFS carriers calculated from a pool of 511 randomly selected SWB horses born in 2017 was equal to 7.4% and ranged from 0.0 to 12.0% among the whole set of tested SWB horses, starting from 1971 till 2020. The effect of the WFFS carrier genotype was significant for several EBV mainly related to movements and dressage traits and especially for horses not bred for the show jumping discipline. Using simulation, we showed that balancing selection can maintain a recessive lethal allele in populations such as the SWB breed over generations and that the frequency is expected to slowly decrease in absence of balancing selection. Finally, we showed that selection against carrier sires can result in a more rapid decrease of the frequency of the mutant allele over time. Conclusion Further research is needed to confirm the apparent association between equine performance and the WFFS carrier genotype. Identification of such associations or new causative mutations for horse performance traits can serve as new tools in horse breeding to select for healthy, sustainable, and better performing horses. Supplementary Information The online version contains supplementary material available at 10.1186/s12711-021-00693-4.
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Affiliation(s)
- Michela Ablondi
- Department of Veterinary Science, Università degli Studi di Parma, 43126, Parma, Italy
| | - Martin Johnsson
- Dept. of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, PO Box 7023, S-750 07, Uppsala, Sweden
| | - Susanne Eriksson
- Dept. of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, PO Box 7023, S-750 07, Uppsala, Sweden
| | - Alberto Sabbioni
- Department of Veterinary Science, Università degli Studi di Parma, 43126, Parma, Italy
| | - Åsa Gelinder Viklund
- Dept. of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, PO Box 7023, S-750 07, Uppsala, Sweden
| | - Sofia Mikko
- Dept. of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, PO Box 7023, S-750 07, Uppsala, Sweden.
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Flanagan S, Rowe Á, Duggan V, Markle E, O’Brien M, Barry G. Development of a real-time PCR assay to detect the single nucleotide polymorphism causing Warmblood Fragile Foal Syndrome. PLoS One 2021; 16:e0259316. [PMID: 34748589 PMCID: PMC8575260 DOI: 10.1371/journal.pone.0259316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 09/20/2021] [Indexed: 11/19/2022] Open
Abstract
Warmblood Fragile Foal syndrome (WFFS) is an autosomal recessive condition that affects the maturation of collagen in affected foals. Foals affected with the disease typically die or are euthanised shortly after birth. WFFS is caused by a single nucleotide change at position 2032 of the equine PLOD1 gene, causing an impairment of the wild-type enzyme. A commercial test for the causative genetic mutation is currently available from companies operating under licence from Cornell University but it has limitations. This test requires amplification of a region of the PLOD1 gene encompassing the site of interest, followed by Sanger sequencing of that region and computational analysis. We describe here the development of an alternative, real-time PCR based assay that rapidly and reliably differentiates between the wild-type and WFFS associated nucleotides without the need for sequencing, thus increasing the potential for high throughput analysis of large numbers of samples in a cost-effective manner.
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Affiliation(s)
- Sharon Flanagan
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin, Ireland
| | - Áine Rowe
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin, Ireland
| | - Vivienne Duggan
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin, Ireland
| | - Erin Markle
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin, Ireland
| | - Maureen O’Brien
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin, Ireland
| | - Gerald Barry
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin, Ireland
- * E-mail:
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11
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Vroman R, Malfait AM, Miller RE, Malfait F, Syx D. Animal Models of Ehlers-Danlos Syndromes: Phenotype, Pathogenesis, and Translational Potential. Front Genet 2021; 12:726474. [PMID: 34712265 PMCID: PMC8547655 DOI: 10.3389/fgene.2021.726474] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 08/10/2021] [Indexed: 01/09/2023] Open
Abstract
The Ehlers–Danlos syndromes (EDS) are a group of heritable connective tissues disorders mainly characterized by skin hyperextensibility, joint hypermobility and generalized tissue fragility. Currently, 14 EDS subtypes each with particular phenotypic features are recognized and are caused by genetic defects in 20 different genes. All of these genes are involved in the biosynthesis and/or fibrillogenesis of collagens at some level. Although great progress has been made in elucidating the molecular basis of different EDS subtypes, the pathogenic mechanisms underlying the observed phenotypes remain poorly understood, and consequentially, adequate treatment and management options for these conditions remain scarce. To date, several animal models, mainly mice and zebrafish, have been described with defects in 14 of the 20 hitherto known EDS-associated genes. These models have been instrumental in discerning the functions and roles of the corresponding proteins during development, maturation and repair and in portraying their roles during collagen biosynthesis and/or fibrillogenesis, for some even before their contribution to an EDS phenotype was elucidated. Additionally, extensive phenotypical characterization of these models has shown that they largely phenocopy their human counterparts, with recapitulation of several clinical hallmarks of the corresponding EDS subtype, including dermatological, cardiovascular, musculoskeletal and ocular features, as well as biomechanical and ultrastructural similarities in tissues. In this narrative review, we provide a comprehensive overview of animal models manifesting phenotypes that mimic EDS with a focus on engineered mouse and zebrafish models, and their relevance in past and future EDS research. Additionally, we briefly discuss domestic animals with naturally occurring EDS phenotypes. Collectively, these animal models have only started to reveal glimpses into the pathophysiological aspects associated with EDS and will undoubtably continue to play critical roles in EDS research due to their tremendous potential for pinpointing (common) signaling pathways, unveiling possible therapeutic targets and providing opportunities for preclinical therapeutic interventions.
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Affiliation(s)
- Robin Vroman
- Center for Medical Genetics, Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Anne-Marie Malfait
- Division of Rheumatology, Rush University Medical Center, Chicago, IL, United States
| | - Rachel E Miller
- Division of Rheumatology, Rush University Medical Center, Chicago, IL, United States
| | - Fransiska Malfait
- Center for Medical Genetics, Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Delfien Syx
- Center for Medical Genetics, Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
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12
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Rowe Á, Flanagan S, Barry G, Katz LM, Lane EA, Duggan V. Warmblood fragile foal syndrome causative single nucleotide polymorphism frequency in horses in Ireland. Ir Vet J 2021; 74:27. [PMID: 34663462 PMCID: PMC8524838 DOI: 10.1186/s13620-021-00206-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 10/04/2021] [Indexed: 11/30/2022] Open
Abstract
Background Warmblood Fragile Foal Syndrome (WFFS) is an autosomal recessive disorder caused by a mutation in the procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 (PLOD1) gene. Homozygosity for the mutation results in defective collagen synthesis which clinically manifests as the birth of non viable or still born foals with abnormally fragile skin. While the mutation has been identified in non Warmblood breeds including the Thoroughbred, to date all homozygous clinically affected cases reported in the scientific literature are Warmblood foals. The objective of this study was to investigate the carrier frequency of the mutation in the Thoroughbred and sport horse populations in Ireland. Methods A test was developed at the UCD School of Veterinary Medicine using real-time PCR to amplify the PLOD1 gene c.2032G > A variant. A subset of the samples was also submitted to an external laboratory with a licensed commercial WFFS genetic test. Results Warmblood Fragile Foal Syndrome genotyping was performed on hair samples from 469 horses representing 6 different breeds. Six of 303 (1.98%) sport horses tested and three of 109 (2.75%) Thoroughbreds tested were heterozygous for the WFFS polymorphism (N/WFFS). The WFFS polymorphism was not identified in the Standardbred, Cob, Connemara, or other pony breeds. Conclusions The study identified a low frequency of the WFFS causative mutation in sport horses and Thoroughbreds in Ireland, highlighting the importance of WFFS genetic testing in order to identify phenotypically normal heterozygous carriers and to prevent the birth of nonviable foals.
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Affiliation(s)
- Áine Rowe
- Veterinary Sciences Centre, School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Sharon Flanagan
- Veterinary Sciences Centre, School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - Gerald Barry
- Veterinary Sciences Centre, School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - Lisa M Katz
- Veterinary Sciences Centre, School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - Elizabeth A Lane
- Animal Health Division, Department of Agriculture, Food and the Marine, Backweston Campus, Celbridge, Co. Kildare, W23 X3PH, Ireland
| | - Vivienne Duggan
- Veterinary Sciences Centre, School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
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13
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Brooks SA. Genomics in the Horse Industry: Discovering New Questions at Every Turn. J Equine Vet Sci 2021; 100:103456. [PMID: 34030792 DOI: 10.1016/j.jevs.2021.103456] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 10/21/2022]
Abstract
The sheer diversity of heritable physiological traits, and the ingenuity of genome derived research technologies, extends the study of genetics to impact diverse scientific fields. Equine science is no exception, experiencing a number of genome-enabled discoveries that spur further research in areas like nutrition, reproduction, and exercise physiology. Yet unexpected findings, especially those that over-turn commonly held beliefs in the horse industry, can create challenges in outreach, education and communication with stakeholders. For example, studies of ancient DNA revealed that the oldest domesticated equids in the archeological record were in fact another species, the Przewalski's horse, leaving the origins of our modern horses a mystery yet to be solved. Genomic analysis of ancestry can illuminate relationships older than our prized pedigree records, and in some cases, identify unexpected inconsistencies in those pedigrees. Even our interpretation of what constitutes a genetic disease is changing, as we re-examine common disease alleles; how these alleles impact equine physiology, and how they are perceived by breeders and professionals in the industry. Effectively translating genetic tools for utilization in horse management and preparing our community for the debate surrounding ethical questions that may arise from genomic studies, may be the next great challenges we face as scientists and educators.
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Affiliation(s)
- Samantha A Brooks
- Department of Animal Sciences and the UF Genetics Institute, University of Florida, Gainesville Fl.
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14
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Distribution of the Warmblood Fragile Foal Syndrome Type 1 Mutation (PLOD1 c.2032G>A) in Different Horse Breeds from Europe and the United States. Genes (Basel) 2020; 11:genes11121518. [PMID: 33353040 PMCID: PMC7766603 DOI: 10.3390/genes11121518] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/16/2020] [Accepted: 12/16/2020] [Indexed: 11/23/2022] Open
Abstract
Warmblood fragile foal syndrome (WFFS) is an autosomal recessive disorder caused by a single nucleotide variant in the procollagen-lysine-2-oxoglutarate-5-dioxygenase 1 gene (PLOD1:c.2032G>A, p.Gly678Arg). Homozygosity for the PLOD1 variant causes an Ehler-Danlos-like syndrome, which has to date only been reported in warmblood breeds but the WFFS allele has been also detected in the Thoroughbred. To investigate the breed distribution of the WFFS allele, 4081 horses belonging to 38 different breeds were screened. In total, 4.9% of the horses representing 21 breeds carried the WFFS allele. The affected breeds were mainly warmbloods, with carrier frequency as high as 17% in the Hanoverian and Danish Warmblood. The WFFS allele was not detected in most non-warmblood breeds. Exceptions include WFFS carriers in the Thoroughbred (17/716), Haflinger (2/48), American Sport Pony (1/12), and Knabstrupper (3/46). The origin of the WFFS allele remains unknown. The Arabian breed and specifically the stallion Bairactar Or. Ar. (1813), whose offspring were reported to have a similar phenotype in the 19th century, were hypothesized as the origin. DNA from a museum sample of Bairactar Or. Ar. showed that he did not carry the mutated allele. This result, together with the genotypes of 302 Arabians, all homozygous for the reference allele, does not support an Arabian origin of the WFFS allele. Our extensive survey shows the WFFS allele to be of moderate frequency and concern in warmbloods and also in breeds where it may not be expected.
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15
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Martin K, Brooks S, Vierra M, Lafayette WT, McClure S, Carpenter M, Lafayette C. Fragile Foal Syndrome (PLOD1 c.2032G>A) occurs across diverse horse populations. Anim Genet 2020; 52:137-138. [PMID: 33165934 DOI: 10.1111/age.13020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2020] [Indexed: 11/28/2022]
Affiliation(s)
| | - Samantha Brooks
- Department of Animal Science, UF Genetics Institute, University of Florida, Gainesville, FL, 32611, USA
| | | | | | - Scott McClure
- Scott McClure, Midwest Equine, Boone, IA, 50036, USA
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Jacinto JGP, Häfliger IM, Veiga IMB, Letko A, Benazzi C, Bolcato M, Drögemüller C. A Heterozygous Missense Variant in the COL5A2 in Holstein Cattle Resembling the Classical Ehlers-Danlos Syndrome. Animals (Basel) 2020; 10:ani10112002. [PMID: 33143196 PMCID: PMC7692662 DOI: 10.3390/ani10112002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 10/26/2020] [Accepted: 10/28/2020] [Indexed: 12/22/2022] Open
Abstract
Simple Summary Genodermatoses represent inherited disorders of the skin that mostly follow a monogenic mode of inheritance. Heritable connective tissue disorders such as classical Ehlers–Danlos syndrome (cEDS) belong to this group of human rare diseases that sporadically occur in other species. Herein, affected cattle are reported showing skin lesions including cutis laxa clinically and pathologically resembling cEDS in humans. Microscopic findings in the deeper dermis were consistent with collagen dysplasia. Whole-genome sequencing (WGS) identified a most likely disease-causing mutation in the COL5A2 gene. The COL5A2 gene is known to be associated with dominant inherited cEDS forms in mice and humans, but so far, it was not shown to cause a similar phenotype in domestic animals. The disease phenotype examined herein showed co-segregation with the identified missense variant within the maternal line across two generations and is most likely due to a spontaneous mutation event. Rare non-lethal disorders such as cEDS in livestock are mostly not diagnosed, but might affect animal welfare and thus lower the value of affected animals. WGS-based precision diagnostics allows understanding rare disorders and supports the value of surveillance of cattle breeding populations for harmful genetic disorders. Abstract Classical Ehlers–Danlos syndrome (cEDS) is a heritable connective tissue disorder characterized by variable degrees of skin hyperextensibility and fragility, atrophic scarring, and generalized joint hypermobility. The purpose of this study was to characterize the clinicopathological phenotype of a cEDS-affected Holstein calf and to identify the causative genetic variant associated with the disorder by whole-genome sequencing (WGS). A 3-day-old female Holstein calf was referred because of easily induced skin detachment and hyperextensibility in the neck. A complete clinical investigation was performed in the calf, dam, and maternal-grandmother. The calf and dam showed hyperextensibility of the neck skin and atrophic scarring; additionally, the calf presented skin fragility. Moreover, the histopathology of biopsies from the calf and its dam showed that the collagen bundles in affected skin areas were wavy, short, thin, and surrounded by edema and moderate to severe acute hemorrhages. Genetic analysis revealed a private heterozygous missense variant in COL5A2 (c.2366G>T; p.Gly789Val) that was present only in the calf and dam. This confirmed the diagnosis of cEDS and represents the first report of a causal variant for cEDS in cattle and the first COL5A2-related large animal model.
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Affiliation(s)
- Joana G. P. Jacinto
- Department of Veterinary Medical Sciences, University of Bologna, 40064 Ozzano Emilia (Bologna), Italy; (J.G.P.J.); (C.B.); (M.B.)
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland; (I.M.H.); (A.L.)
| | - Irene M. Häfliger
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland; (I.M.H.); (A.L.)
| | - Inês M. B. Veiga
- Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland;
| | - Anna Letko
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland; (I.M.H.); (A.L.)
| | - Cinzia Benazzi
- Department of Veterinary Medical Sciences, University of Bologna, 40064 Ozzano Emilia (Bologna), Italy; (J.G.P.J.); (C.B.); (M.B.)
| | - Marilena Bolcato
- Department of Veterinary Medical Sciences, University of Bologna, 40064 Ozzano Emilia (Bologna), Italy; (J.G.P.J.); (C.B.); (M.B.)
| | - Cord Drögemüller
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland; (I.M.H.); (A.L.)
- Correspondence:
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Haythorn A, Young M, Stanton J, Zhang J, Mueller POE, Halper J. Differential gene expression in skin RNA of horses affected with degenerative suspensory ligament desmitis. J Orthop Surg Res 2020; 15:460. [PMID: 33028365 PMCID: PMC7541307 DOI: 10.1186/s13018-020-01994-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 10/01/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Equine degenerative suspensory ligament desmitis (DSLD) is a systemic connective tissue disorder first identified in Peruvian Paso horses but afflicting other horse breeds as well. Inappropriate accumulation of proteoglycans in connective tissues, most prominently in tendons and ligaments, leads to progressive and debilitating lameness and pain. It is largely unknown what drives the overproduction of proteoglycans, but our previous studies suggest involvement of bone morphogenetic protein 2 (BMP2), a member of the transforming growth factor-β (TGFβ) family, impacting synthesis of proteoglycans. To identify potential players in pathogenesis of DSLD a new approach utilizing next generation sequencing was undertaken. METHODS Next generation sequencing was performed using RNA extracted from skin biopsies of six control Peruvian Pasos and six horses with DSLD (4 Peruvian Pasos and 2 warmbloods). The CuffDiff result sets were validated with algorithms used to run them. This was based on the determined false discovery rates derived from the P values adjusted for multiple testing for any given result. RESULTS Bioinformatics analysis of transcriptomes revealed differential expression of over 1500 genes, including increased expression of genes for several growth factors (most prominently BMP2, FGF5, CTGF, many members of the EGF family), and mediators of signaling (Fos, Myc, MAPK system), and keratins. Two genes encoding for enzymes involved in synthesis of hyaluronan were also overexpressed. Gene expression was decreased for protein cores of many proteoglycans, several growth factors, most collagens, and many peptides with immune function. CONCLUSIONS The overexpression of BMP2 correlates well with our previous data. However, the decrease in expression of numerous proteoglycans was unexpected. A mutation in a gene of a less characterized proteoglycan and/or glycosyltransferase with subsequent increased production of hyaluronan and/or a proteoglycan(s) undetected in our study could account for the systemic proteoglycan deposition. Decreased collagen gene expression indicates abnormal connective tissue metabolism. The increased expression of keratin genes and FGF5 supports reports of skin abnormalities in DSLD. Underexpression of immune function genes corresponds with lack of inflammation in DSLD tissues. Finally, though the proteoglycan and/or glycosaminoglycan abundant in DSLD has not been identified, we validated our previous data, including overexpression of BMP2, and systemic nature of DSLD due to disturbed metabolism of the extracellular matrix.
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Affiliation(s)
- Abigail Haythorn
- Department of Pathology, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602 USA
| | - Madeline Young
- Department of Pathology, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602 USA
| | - James Stanton
- Department of Pathology, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602 USA
| | - Jian Zhang
- Department of Pathology, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602 USA
| | - P. O. E. Mueller
- Department of Large Animal Medicine, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602 USA
| | - Jaroslava Halper
- Department of Pathology, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602 USA
- AU/UGA Medical Partnership, The University of Georgia, Athens, GA 30602 USA
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Lindgren G, Naboulsi R, Frey R, Solé M. Genetics of Skin Disease in Horses. Vet Clin North Am Equine Pract 2020; 36:323-339. [PMID: 32534850 DOI: 10.1016/j.cveq.2020.03.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Equine skin diseases are common, causing increased costs and reduced welfare of affected horses.Genetic testing, if available, can complement early detection, disease diagnosis, and clinical treatment and offers horse breeders the possibility to rule out carrier status. The mechanisms of complex disease can be investigated by using the latest state-of-the-art genomic technologies. Genome-based strategies may also serve as an efficient and cost-effective strategy for the management of the disease severity levels, with particular interest in complex traits such as insect bite hypersensitivity, chronic progressive lymphedema, and melanoma.
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Affiliation(s)
- Gabriella Lindgren
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Almas Allé 8, Uppsala 75007, Sweden; Livestock Genetics, Department of Biosystems, KU Leuven Leuven, KasteelparkArenberg 30, Leuven 3001, Belgium
| | - Rakan Naboulsi
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Almas Allé 8, Uppsala 75007, Sweden
| | - Rebecka Frey
- AniCura Norsholms Djursjukhus, Norsholm 61791, Sweden
| | - Marina Solé
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Almas Allé 8, Uppsala 75007, Sweden.
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Abstract
Genetic testing in horses began in the 1960s, when parentage testing using blood group markers became the standard. In the 1990s, parentage testing shifted from evaluating blood groups to DNA testing. The development of genetics and genomics in both human and veterinarian medicine, along with continued technological advances in the last 2 decades, has helped unravel the causal variants for many horse traits. Genetic testing is also now possible for a variety of phenotypic and disease traits and is used to assist in breeding and clinical management decisions. This article describes the genetic tests that are currently available for horses.
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Affiliation(s)
- Rebecca R Bellone
- Department of Population Health and Reproduction Davis, CA 95616, USA; Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA.
| | - Felipe Avila
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA
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Metzger J, Kreft O, Sieme H, Martinsson G, Reineking W, Hewicker-Trautwein M, Distl O. Hanoverian F/W-line contributes to segregation of Warmblood fragile foal syndrome type 1 variant PLOD1:c.2032G>A in Warmblood horses. Equine Vet J 2020; 53:51-59. [PMID: 32323341 DOI: 10.1111/evj.13271] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 03/23/2020] [Accepted: 04/04/2020] [Indexed: 01/06/2023]
Abstract
BACKGROUND Warmblood fragile foal syndrome (WFFS) is a lethal condition detected in Warmblood horses. Its origin and association with performance traits and fertility among horse populations is unknown. OBJECTIVES To validate the previously identified WFFS type 1 (WFFST1)-associated missense variant PLOD1:c.2032G>A and to investigate its distribution among various horses with particular focus on Hanoverian breed, as well as its pathomorphological picture. The study aimed at identifying the origin of the mutant allele and its correlation with performance and fertility traits in Warmblood horses. STUDY DESIGN Retrospective case-control and association study. METHODS WFFST1 variant was validated using whole genome sequencing (WGS) in 78 equids. In an affected foal with a homozygous mutant genotype, necropsy was performed. Skin samples were examined using histology and transmission electron microscopy. Pathway analysis was performed to trace back 81 genetic carriers to the most common recent ancestor. Furthermore, generalised linear model analysis was employed to test estimated breeding values (EBVs) for differences in performance and fertility traits among different genotypes in Hanoverian horses. RESULTS WFFST1 variant had the lowest minor allele frequency among all variants detected in WGS data in the region of PLOD1. Further genotyping of this variant revealed allele frequencies of 0.14 in Hanoverian horses. Histological investigations of the WFFST1-affected foal showed loosely arranged collagen fibres in the dermis. Ultrastructurally, multifocal areas with degraded collagen fibrils and fibrillar plaques were detected. Further pathway analysis revealed a stallion from the Hanoverian sire F/W line as the most common recent ancestor of all tested genetic carriers. Furthermore, WFFST1 variant was found to be correlated with EBVs for gait-related traits as well as conformation and dressage. MAIN LIMITATIONS Study evaluated carriers and cases only from Europe. CONCLUSIONS This study provides a comprehensive evaluation of WFFST1 variant and traces it back to its potential origin.
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Affiliation(s)
- Julia Metzger
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine, Hannover, Germany
| | | | - Harald Sieme
- Unit of Reproductive Medicine of the Clinics, University of Veterinary Medicine, Hannover, Germany
| | | | - Wencke Reineking
- Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany
| | | | - Ottmar Distl
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine, Hannover, Germany
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Ablondi M, Eriksson S, Tetu S, Sabbioni A, Viklund Å, Mikko S. Genomic Divergence in Swedish Warmblood Horses Selected for Equestrian Disciplines. Genes (Basel) 2019; 10:E976. [PMID: 31783652 PMCID: PMC6947233 DOI: 10.3390/genes10120976] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/20/2019] [Accepted: 11/23/2019] [Indexed: 01/12/2023] Open
Abstract
The equestrian sport horse Swedish Warmblood (SWB) originates from versatile cavalry horses. Most modern SWB breeders have specialized their breeding either towards show jumping or dressage disciplines. The aim of this study was to explore the genomic structure of SWB horses to evaluate the presence of genomic subpopulations, and to search for signatures of selection in subgroups of SWB with high or low breeding values (EBVs) for show jumping. We analyzed high density genotype information from 380 SWB horses born in the period 2010-2011, and used Principal Coordinates Analysis and Discriminant Analysis of Principal Components to detect population stratification. Fixation index and Cross Population Extended Haplotype Homozygosity scores were used to scan the genome for potential signatures of selection. In accordance with current breeding practice, this study highlights the development of two separate breed subpopulations with putative signatures of selection in eleven chromosomes. These regions involve genes with known function in, e.g., mentality, endogenous reward system, development of connective tissues and muscles, motor control, body growth and development. This study shows genetic divergence, due to specialization towards different disciplines in SWB horses. This latter evidence can be of interest for SWB and other horse studbooks encountering specialized breeding.
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Affiliation(s)
- Michela Ablondi
- Department of Veterinary Science, University of Parma, 43126 Parma, Italy; (M.A.); (A.S.)
| | - Susanne Eriksson
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, PO Box 7023, S-75007 Uppsala, Sweden; (S.E.); (S.T.); (Å.V.)
| | - Sasha Tetu
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, PO Box 7023, S-75007 Uppsala, Sweden; (S.E.); (S.T.); (Å.V.)
| | - Alberto Sabbioni
- Department of Veterinary Science, University of Parma, 43126 Parma, Italy; (M.A.); (A.S.)
| | - Åsa Viklund
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, PO Box 7023, S-75007 Uppsala, Sweden; (S.E.); (S.T.); (Å.V.)
| | - Sofia Mikko
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, PO Box 7023, S-75007 Uppsala, Sweden; (S.E.); (S.T.); (Å.V.)
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Aurich C, Müller-Herbst S, Reineking W, Müller E, Wohlsein P, Gunreben B, Aurich J. Characterization of abortion, stillbirth and non-viable foals homozygous for the Warmblood Fragile Foal Syndrome. Anim Reprod Sci 2019; 211:106202. [PMID: 31785623 DOI: 10.1016/j.anireprosci.2019.106202] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 09/30/2019] [Accepted: 10/09/2019] [Indexed: 11/26/2022]
Abstract
Warmblood fragile foal syndrome (WFFS) is a monogenetic defect with autosomal recessive inheritance. The WFFS homozygosity is non-compatible with extra-uterine life. Although as many as 15% of Warmblood horses are WFFS carriers, there has been little veterinary focus on this condition. The aim of this study was to determine outcomes and symptoms of clinical signs and pathological abnormalities during pregnancies when there were WFFS homozygous foetuses. Diagnostic material of 15 abortion or stillbirth cases with suspected diagnosis of WFFS was available for this study. Additionally, there were examinations in 37 cases where there were no indications of WFFS when submitted for routine diagnostic procedures. Foals in all cases were genotyped and external morphological defects were recorded. Amongst the 15 cases in which WFSS was suspected, there were 14 homozygous foetuses with the WFFS allele (WFFS/WFFS). Three heterozygous WFFS foetuses (N/WFFS) were detected in the cases submitted for routine diagnostic procedures. Of the 14 WFFS homozygous foetuses, 11 of mares had a gestation length of at least 320 days. Nine foals were born alive but died within a short time. Skin defects were obvious in 12 WFFS homozygous foals, and there was abnormal flexibility in the digital joints, flexed forelegs and incomplete closure of the abdominal wall in five, four, and one of the foals, respectively. In conclusion, the predominant manifestation of WFFS are death during the latter stages of gestation or live births with foals being non-viable. Losses in Warmblood horse breeding caused by WFFS are greater than previously assumed.
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Affiliation(s)
- Christine Aurich
- Artificial Insemination and Embryo Transfer, Department of Small Animals and Horses, Vetmeduni Vienna, 1210 Vienna, Austria.
| | | | - Wencke Reineking
- Department of Pathology, University of Veterinary Medicine, 30559 Hannover, Germany
| | | | - Peter Wohlsein
- Department of Pathology, University of Veterinary Medicine, 30559 Hannover, Germany
| | | | - Jörg Aurich
- Obstetrics, Gynaecology and Andrology, Department of Small Animals and Horses, Vetmeduni Vienna, 1210 Vienna, Austria
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Bellone RR, Ocampo NR, Hughes SS, Le V, Arthur R, Finno CJ, Penedo MCT. Warmblood fragile foal syndrome type 1 mutation (PLOD1 c.2032G>A) is not associated with catastrophic breakdown and has a low allele frequency in the Thoroughbred breed. Equine Vet J 2019; 52:411-414. [PMID: 31502696 PMCID: PMC7062577 DOI: 10.1111/evj.13182] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 08/30/2019] [Indexed: 01/19/2023]
Abstract
Background Catastrophic fractures are among the most common cause of fatalities in racehorses. Several factors, including genetics, likely contribute to increased risk for fatal injuries. A variant in the procollagen‐lysine, 2‐oxoglutarate 5‐dioxygenase1 gene (PLOD1 c.2032G>A) was shown to cause Warmblood fragile foal syndrome type 1 (WFFS), a fatal recessive defect of the connective tissue. Screening of multiple horse breeds identified the presence of the WFFS allele in the Thoroughbred. PLOD1 is involved in cross‐linking of collagen fibrils and thus could potentially increase the risk of catastrophic breakdown. Objectives Estimate the frequency of the WFFS allele (PLOD1 c.2032G>A) and determine if it is a risk factor for catastrophic breakdown in the Thoroughbred. Study design Case–control genetic study. Methods Genomic DNA from hair and/or tissue samples was genotyped for the WFFS allele. Fisher’s Exact tests were performed to compare allele and carrier frequencies between the case cohort (catastrophic breakdown, n = 22) and several cohorts with no record of injury (n = 138 raced/trained at same track and season and n = 185 older than 7 years and raced during same season), nonracers (n = 92), and a random sample without consideration for racing history (n = 279). Results The frequency of the PLOD1 c.2032G>A variant in the Thoroughbred breed is low (1.2%). Seventeen of 716 Thoroughbreds tested were carriers (2.4%) and no WFFS homozygotes were detected. Only one catastrophic breakdown case carried the WFFS allele. No statistically significant difference in allele or carrier frequency was identified between case and control cohorts (P>0.05 in all comparisons performed). Main limitations This study evaluated cases from one single track. Conclusions This study demonstrated that the PLOD1 c.2032G>A associated with WFFS is present at very low frequency in Thoroughbreds and is not a genetic risk factor for catastrophic breakdown.
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Affiliation(s)
- R R Bellone
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, California, USA.,Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
| | - N R Ocampo
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
| | - S S Hughes
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
| | - V Le
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
| | - R Arthur
- School of Veterinary Medicine, University of California-Davis, Davis, California, USA
| | - C J Finno
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
| | - M C T Penedo
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
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Bauer A, de Lucia M, Leuthard F, Jagannathan V, Leeb T. Compound heterozygosity for TNXB genetic variants in a mixed-breed dog with Ehlers-Danlos syndrome. Anim Genet 2019; 50:546-549. [PMID: 31365140 DOI: 10.1111/age.12830] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/25/2019] [Indexed: 11/30/2022]
Abstract
The Ehlers-Danlos syndromes (EDSs) are a heterogeneous group of inherited connective tissue disorders characterized by skin hyperextensibility, joint hypermobility and tissue fragility. Inherited disorders similar to human EDS have been reported in different mammalian species. In the present study, we investigated a female mixed-breed dog with clinical signs of EDS. Whole-genome sequencing of the affected dog revealed two missense variants in the TNXB gene, encoding the extracellular matrix protein tenascin XB. In humans, TNXB genetic variants cause classical-like EDS or the milder hypermobile EDS. The affected dog was heterozygous at both identified variants. Each variant allele was transmitted from one of the case's parents, consistent with compound heterozygosity. Although one of the variant alleles, XM_003431680.3:c.2012G>A, p.(Ser671Asn), was private to the family of the affected dog and absent from whole-genome sequencing data of 599 control dogs, the second variant allele, XM_003431680.3:c.2900G>A, p.(Gly967Asp), is present at a low frequency in the Chihuahua and Poodle population. Given that TNXB is a functional candidate gene for EDS, we suggest that compound heterozygosity for the identified TNXB variants may have caused the EDS-like phenotype in the affected dog. Chihuahuas and Poodles should be monitored for EDS cases, which might confirm the hypothesized pathogenic effect of the segregating TNXB variant.
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Affiliation(s)
- A Bauer
- Vetsuisse Faculty, Institute of Genetics, University of Bern, 3001, Bern, Switzerland.,DermFocus, University of Bern, 3001, Bern, Switzerland
| | - M de Lucia
- San Marco Veterinary Clinic and Laboratory, Via Dell'Industria 3, 35030, Veggiano, Italy
| | - F Leuthard
- Vetsuisse Faculty, Institute of Genetics, University of Bern, 3001, Bern, Switzerland.,DermFocus, University of Bern, 3001, Bern, Switzerland
| | - V Jagannathan
- Vetsuisse Faculty, Institute of Genetics, University of Bern, 3001, Bern, Switzerland.,DermFocus, University of Bern, 3001, Bern, Switzerland
| | - T Leeb
- Vetsuisse Faculty, Institute of Genetics, University of Bern, 3001, Bern, Switzerland.,DermFocus, University of Bern, 3001, Bern, Switzerland
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25
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Warmblood Fragile Foal Syndrome causative single nucleotide polymorphism frequency in Warmblood horses in Brazil. Vet J 2019; 248:101-102. [PMID: 31113555 DOI: 10.1016/j.tvjl.2019.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 05/02/2019] [Accepted: 05/03/2019] [Indexed: 11/20/2022]
Abstract
Warmblood Fragile Foal Syndrome (WFFS) is an autosomal recessive genetic disorder caused by a mutation in the procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 (PLOD1) gene, associated with collagen biosynthesis. WFFS causes lesions and malformations of the skin in neonatal foals, and abortion. The objective of this study was to investigate the allelic frequency of the single nucleotide polymorphism (SNP) c.2032G>A in the PLOD1 gene in warmblood samples from Brazil. Of the 374 Warmblood horses tested, 41 animals (11%) were identified as heterozygous for the WFFS SNP and 333 (89%) were homozygous for the wild-type allele (N/N), and therefore, the allele frequency was 5.5%. This study highlights the importance of control measures to prevent an increase in the incidence of WFFS in Warmblood horses worldwide.
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26
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Spycher M, Bauer A, Jagannathan V, Frizzi M, De Lucia M, Leeb T. A frameshift variant in the COL5A1 gene in a cat with Ehlers-Danlos syndrome. Anim Genet 2018; 49:641-644. [PMID: 30246406 DOI: 10.1111/age.12727] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2018] [Indexed: 11/27/2022]
Abstract
Ehlers-Danlos syndrome (EDS) is a group of heritable connective tissue disorders caused by defective collagen synthesis or incorrect assembly of the collagen triple helical structure. EDS is characterised by joint hypermobility, skin hyperextensibility, abnormal scarring, poor wound healing and tissue friability. Human EDS may be caused by variants in several different genes including COL5A1, which encodes the collagen type V alpha 1 chain. For the present study we investigated a 1.5-year-old, spayed female, domestic shorthair cat with EDS. The affected cat showed multiple recurrent skin tears, hyperextensibility of the skin and joint abnormalities. We obtained whole genome sequencing data from the affected cat and searched for variants in candidate genes known to cause EDS. We detected a heterozygous single base-pair deletion in exon 43 of the COL5A1 gene, namely c.3420delG. The deletion was predicted to result in a frameshift and premature stop codon: p.(Leu1141SerfsTer134). Sanger sequencing confirmed that the variant was present in the affected cat and absent from 103 unaffected cats from different breeds. The variant was also absent from a Burmese cat with EDS. Based on knowledge about the functional impact of COL5A1 variants in other species, COL5A1:c.3420delG represents a compelling candidate causative variant for the observed EDS in the affected cat.
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Affiliation(s)
- M Spycher
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001, Bern, Switzerland.,DermFocus, University of Bern, 3001, Bern, Switzerland
| | - A Bauer
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001, Bern, Switzerland.,DermFocus, University of Bern, 3001, Bern, Switzerland
| | - V Jagannathan
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001, Bern, Switzerland.,DermFocus, University of Bern, 3001, Bern, Switzerland
| | - M Frizzi
- San Marco Veterinary Clinic, Via Sorio 114/C, 35141, Padova, Italy
| | - M De Lucia
- San Marco Veterinary Clinic, Via Sorio 114/C, 35141, Padova, Italy.,San Marco Veterinary Laboratory, Via Sorio 114/C, 35141, Padova, Italy
| | - T Leeb
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001, Bern, Switzerland.,DermFocus, University of Bern, 3001, Bern, Switzerland
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Oliveira-Filho JP, Badial PR, Liboreiro RM, Conceição LG, Winand NJ, Borges AS. Ehlers-Danlos Syndrome in a Mangalarga–Campolina Crossbreed Mare. J Equine Vet Sci 2017. [DOI: 10.1016/j.jevs.2017.07.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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28
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Rashmir-Raven AM, Spier SJ. Hereditary equine regional dermal asthenia (HERDA) in Quarter Horses: A review of clinical signs, genetics and research. EQUINE VET EDUC 2015. [DOI: 10.1111/eve.12459] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- A. M. Rashmir-Raven
- Large Animal Clinical Sciences; College of Veterinary Medicine; Michigan State University; East Lansing USA
| | - S. J. Spier
- Department of Medicine and Epidemiology; School of Veterinary Medicine; University of California; Davis USA
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