1
|
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] [What about the content of this article? (0)] [Affiliation(s)] [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.
Collapse
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
| |
Collapse
|
2
|
Durward-Akhurst SA, Schaefer RJ, Grantham B, Carey WK, Mickelson JR, McCue ME. Genetic Variation and the Distribution of Variant Types in the Horse. Front Genet 2021; 12:758366. [PMID: 34925451 PMCID: PMC8676274 DOI: 10.3389/fgene.2021.758366] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 11/10/2021] [Indexed: 11/13/2022] Open
Abstract
Genetic variation is a key contributor to health and disease. Understanding the link between an individual's genotype and the corresponding phenotype is a major goal of medical genetics. Whole genome sequencing (WGS) within and across populations enables highly efficient variant discovery and elucidation of the molecular nature of virtually all genetic variation. Here, we report the largest catalog of genetic variation for the horse, a species of importance as a model for human athletic and performance related traits, using WGS of 534 horses. We show the extent of agreement between two commonly used variant callers. In data from ten target breeds that represent major breed clusters in the domestic horse, we demonstrate the distribution of variants, their allele frequencies across breeds, and identify variants that are unique to a single breed. We investigate variants with no homozygotes that may be potential embryonic lethal variants, as well as variants present in all individuals that likely represent regions of the genome with errors, poor annotation or where the reference genome carries a variant. Finally, we show regions of the genome that have higher or lower levels of genetic variation compared to the genome average. This catalog can be used for variant prioritization for important equine diseases and traits, and to provide key information about regions of the genome where the assembly and/or annotation need to be improved.
Collapse
Affiliation(s)
- S. A. Durward-Akhurst
- Department of Veterinary Population Medicine, University of Minnesota, Minneapolis, MN, United States
| | - R. J. Schaefer
- Department of Veterinary Population Medicine, University of Minnesota, Minneapolis, MN, United States
| | - B. Grantham
- Interval Bio LLC, Mountain View, CA, United States
| | - W. K. Carey
- Interval Bio LLC, Mountain View, CA, United States
| | - J. R. Mickelson
- Department of Veterinary and Biomedical Sciences, University of Minnesota, Minneapolis, MN, United States
| | - M. E. McCue
- Department of Veterinary Population Medicine, University of Minnesota, Minneapolis, MN, United States
| |
Collapse
|
3
|
Hisey EA, Hermans H, Lounsberry ZT, Avila F, Grahn RA, Knickelbein KE, Duward-Akhurst SA, McCue ME, Kalbfleisch TS, Lassaline ME, Back W, Bellone RR. Whole genome sequencing identified a 16 kilobase deletion on ECA13 associated with distichiasis in Friesian horses. BMC Genomics 2020; 21:848. [PMID: 33256610 PMCID: PMC7706231 DOI: 10.1186/s12864-020-07265-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 11/23/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Distichiasis, an ocular disorder in which aberrant cilia (eyelashes) grow from the opening of the Meibomian glands of the eyelid, has been reported in Friesian horses. These misplaced cilia can cause discomfort, chronic keratitis, and corneal ulceration, potentially impacting vision due to corneal fibrosis, or, if secondary infection occurs, may lead to loss of the eye. Friesian horses represent the vast majority of reported cases of equine distichiasis, and as the breed is known to be affected with inherited monogenic disorders, this condition was hypothesized to be a simply inherited Mendelian trait. RESULTS A genome wide association study (GWAS) was performed using the Axiom 670 k Equine Genotyping array (MNEc670k) utilizing 14 cases and 38 controls phenotyped for distichiasis. An additive single locus mixed linear model (EMMAX) approach identified a 1.83 Mb locus on ECA5 and a 1.34 Mb locus on ECA13 that reached genome-wide significance (pcorrected = 0.016 and 0.032, respectively). Only the locus on ECA13 withstood replication testing (p = 1.6 × 10- 5, cases: n = 5 and controls: n = 37). A 371 kb run of homozygosity (ROH) on ECA13 was found in 13 of the 14 cases, providing evidence for a recessive mode of inheritance. Haplotype analysis (hapQTL) narrowed the region of association on ECA13 to 163 kb. Whole-genome sequencing data from 3 cases and 2 controls identified a 16 kb deletion within the ECA13 associated haplotype (ECA13:g.178714_195130del). Functional annotation data supports a tissue-specific regulatory role of this locus. This deletion was associated with distichiasis, as 18 of the 19 cases were homozygous (p = 4.8 × 10- 13). Genotyping the deletion in 955 horses from 54 different breeds identified the deletion in only 11 non-Friesians, all of which were carriers, suggesting that this could be causal for this Friesian disorder. CONCLUSIONS This study identified a 16 kb deletion on ECA13 in an intergenic region that was associated with distichiasis in Friesian horses. Further functional analysis in relevant tissues from cases and controls will help to clarify the precise role of this deletion in normal and abnormal eyelash development and investigate the hypothesis of incomplete penetrance.
Collapse
Affiliation(s)
- E A Hisey
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA
| | - H Hermans
- Department of Clinical Sciences, Utrecht University, Yalelaan 112-114, NL-3584, CM, Utrecht, The Netherlands
| | - Z T Lounsberry
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA
| | - F Avila
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA
| | - R A Grahn
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA
| | - K E Knickelbein
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA
- Veterinary Medical Teaching Hospital, University of California-Davis, Davis, CA, USA
| | - S A Duward-Akhurst
- Department of Veterinary Population Medicine, University of Minnesota, Saint Paul, MN, USA
| | - M E McCue
- Department of Veterinary Population Medicine, University of Minnesota, Saint Paul, MN, USA
| | - T S Kalbfleisch
- Department of Veterinary Science, Gluck Equine Research Center, University of Kentucky, Lexington, KY, USA
| | - M E Lassaline
- Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - W Back
- Department of Clinical Sciences, Utrecht University, Yalelaan 112-114, NL-3584, CM, Utrecht, The Netherlands
- Department of Surgery and Anaesthesia of Domestic Animals, Ghent University, Merelbeke, Belgium
| | - R R Bellone
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA.
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA.
| |
Collapse
|
4
|
Cook SR, Conzemius MG, McCue ME, Ekenstedt KJ. SNP-based heritability and genetic architecture of cranial cruciate ligament rupture in Labrador Retrievers. Anim Genet 2020; 51:824-828. [PMID: 32696518 DOI: 10.1111/age.12978] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2020] [Indexed: 01/09/2023]
Abstract
Cranial cruciate ligament rupture (CCLR) is one of the leading causes of pelvic limb lameness in dogs. About 6% of Labrador Retrievers suffer from this orthopedic problem. The aim of this study was to determine the heritability of CCLR in this breed using SNP array genotyping data. DNA samples were collected from CCLR-affected dogs (n = 190) and unaffected dogs over the age of 8 years (n = 143). All 333 dogs were genotyped directly or imputed up to approximately 710k SNPs on the Affymetrix Axiom CanineHD SNP array. Heritability of CCLR was calculated using multiple methodologies, including linear mixed models, Bayesian models and a model that incorporates LD. The covariates of sex and sterilization status were added to each analysis to assess their impact. Across the algorithms of these models, heritability ranged from 0.550 to 0.886, depending on covariate inclusion. The relatively high heritability for this disease indicates that a substantial genetic component contributes to CCLR in the Labrador Retriever.
Collapse
Affiliation(s)
- S R Cook
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, 625 Harrison St, West Lafayette, IN, 47907, USA
| | - M G Conzemius
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, University of Minnesota, 1352 Boyd Avenue, St Paul, MN, 55108, USA
| | - M E McCue
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, 1365 Gortner Avenue, St Paul, MN, 55108, USA
| | - K J Ekenstedt
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, 625 Harrison St, West Lafayette, IN, 47907, USA
| |
Collapse
|
5
|
Roy MM, Norton EM, Rendahl AK, Schultz NE, McFarlane D, Geor RJ, Mickelson JR, McCue ME. Assessment of the FAM174A 11G allele as a risk allele for equine metabolic syndrome. Anim Genet 2020; 51:607-610. [PMID: 32412131 DOI: 10.1111/age.12952] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/20/2020] [Indexed: 11/27/2022]
Abstract
An 11G nucleotide repeat in the 3' UTR of FAM174A was recently postulated as a risk allele with a dominant mode of inheritance for equine metabolic syndrome (EMS) and laminitis status in Arabian horses. The objective of this project was to evaluate this hypothesis in a large and diverse across-breed population. A total of 301 ponies, 292 Morgans, 64 Arabians, 49 Tennessee Walking Horses and 59 Quarter Horses were genotyped for six observed G repeat alleles in the FAM174A 3' UTR. Phenotype data included laminitis status, baseline insulin, glucose, non-esterified fatty acids, triglycerides, adiponectin, leptin, ACTH, insulin and glucose post oral sugar test, and two proxies for insulin resistance. The 11G allele frequencies were 18.8, 6.9, 1.8, 0.2 and 0.0% in the Arabians, Tennessee Walkers, ponies, Morgans and Quarter Horses respectively. Association analyses between FAM174A genotype and EMS phenotypes, and between allele count and EMS phenotypes, identified no statistically significant associations. When a dominant effect for the 11G allele was evaluated, a statistically significant association with adiponectin levels was identified in the ponies, and pairwise comparisons revealed that the estimated marginal means were higher in ponies with the 11G allele vs. alternative alleles (i.e. the allele had a protective effect). In conclusion, our data do not support the FAM174A 11G allele as a risk allele for EMS in our studied breeds.
Collapse
Affiliation(s)
- M M Roy
- Veterinary Population Medicine Department, University of Minnesota, 225 Veterinary Medical Center, 1365 Gortner Ave, St Paul, MN, USA
| | - E M Norton
- Veterinary Population Medicine Department, University of Minnesota, 225 Veterinary Medical Center, 1365 Gortner Ave, St Paul, MN, USA
| | - A K Rendahl
- Veterinary and Biomedical Sciences Department, University of Minnesota, 295 An Sci Vet Med, 1988 Fitch Ave, St Paul, MN, 55108, USA
| | - N E Schultz
- Veterinary Population Medicine Department, University of Minnesota, 225 Veterinary Medical Center, 1365 Gortner Ave, St Paul, MN, USA
| | - D McFarlane
- Department of Physiological Sciences, Oklahoma State University, 264 McElroy Hall, Stillwater, OK, 74078, USA
| | - R J Geor
- College of Sciences, Massey University, B2.13, Science Tower B, Tennent Drive, Palmerston North, New Zealand
| | - J R Mickelson
- Veterinary and Biomedical Sciences Department, University of Minnesota, 295 An Sci Vet Med, 1988 Fitch Ave, St Paul, MN, 55108, USA
| | - M E McCue
- Veterinary Population Medicine Department, University of Minnesota, 225 Veterinary Medical Center, 1365 Gortner Ave, St Paul, MN, USA
| |
Collapse
|
6
|
Beeson SK, Mickelson JR, McCue ME. Equine recombination map updated to EquCab3.0. Anim Genet 2019; 51:341-342. [PMID: 31887785 DOI: 10.1111/age.12898] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 12/05/2019] [Accepted: 12/05/2019] [Indexed: 02/01/2023]
Affiliation(s)
- S K Beeson
- Veterinary Population Medicine Department, 225 Veterinary Medical Center, 1365 Gortner Ave, Saint Paul, 55108, Minnesota, USA
| | - J R Mickelson
- Veterinary and Biomedical Sciences Department, 301 Veterinary Science Building, 1971 Commonwealth Ave, Saint Paul, Minnesota, 55108, USA
| | - M E McCue
- Veterinary Population Medicine Department, 225 Veterinary Medical Center, 1365 Gortner Ave, Saint Paul, 55108, Minnesota, USA
| |
Collapse
|
7
|
McCue ME, McCoy AM. Harnessing big data for equine health. Equine Vet J 2019; 51:429-432. [DOI: 10.1111/evj.13080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M. E. McCue
- University of Minnesota – Veterinary Population Medicine St Paul Minnesota USA
| | - A. M. McCoy
- University of Illinois – Veterinary Clinical Medicine Urbana Illinois USA
| |
Collapse
|
8
|
Durward-Akhurst SA, Schultz NE, Norton EM, Rendahl AK, Besselink H, Behnisch PA, Brouwer A, Geor RJ, Mickelson JR, McCue ME. Associations between endocrine disrupting chemicals and equine metabolic syndrome phenotypes. Chemosphere 2019; 218:652-661. [PMID: 30502704 PMCID: PMC6347404 DOI: 10.1016/j.chemosphere.2018.11.136] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 11/13/2018] [Accepted: 11/21/2018] [Indexed: 05/28/2023]
Abstract
Equine Metabolic Syndrome (EMS) is characterized by abnormalities in insulin regulation, increased adiposity and laminitis, and has several similarities to human metabolic syndrome. A large amount of environmental variability in the EMS phenotype is not explained by commonly measured factors (diet, exercise, and season), suggesting that other environmental factors play a role in EMS development. Endocrine disrupting chemicals (EDCs) are associated with metabolic syndrome and other endocrine abnormalities in humans. This led us to hypothesize that EDCs are detectable in horse plasma and play a role in the pathophysiology of EMS. EDCs acting through the aryl hydrocarbon and estrogen receptors, were measured in plasma of 301 horses from 32 farms. The median (range) TEQ (2,3,7,8-TCDD equivalent) and EEQ (17β-estradiol equivalent) were 19.29 pg/g (0.59-536.36) and 10.50 pg/ml (4.35-15000.00), respectively. TEQ was negatively associated with plasma fat extracted and batch analyzed. EEQ was positively associated with pregnancy and batch analyzed, and negatively associated with being male and superfund score ≤100 miles of the farm. Of particular interest, serum glucose and insulin, glucose and insulin post oral sugar challenge, and leptin concentrations were associated with EEQ, and serum triglyceride concentration was associated with TEQ. Overall, we demonstrated that EDCs are present in the plasma of horses and may explain some of the environmental variability in measured EMS phenotypes. This is the first example of EDCs being associated with clinical disease phenotype components in domestic animals.
Collapse
Affiliation(s)
- S A Durward-Akhurst
- Department of Veterinary Population Medicine, 225 Veterinary Medical Center, 1365 Gortner Avenue, St. Paul, MN, 55108, United States.
| | - N E Schultz
- Department of Veterinary Population Medicine, 225 Veterinary Medical Center, 1365 Gortner Avenue, St. Paul, MN, 55108, United States
| | - E M Norton
- Department of Veterinary Population Medicine, 225 Veterinary Medical Center, 1365 Gortner Avenue, St. Paul, MN, 55108, United States
| | - A K Rendahl
- College of Veterinary Medicine, 1988 Fitch Avenue, St. Paul, 55108, United States
| | - H Besselink
- BioDetection Systems b.v., Science Park 406, 1098 XH Amsterdam, the Netherlands
| | - P A Behnisch
- BioDetection Systems b.v., Science Park 406, 1098 XH Amsterdam, the Netherlands
| | - A Brouwer
- BioDetection Systems b.v., Science Park 406, 1098 XH Amsterdam, the Netherlands
| | - R J Geor
- College of Sciences, B2.13, Science Tower B, Massey University, Palmerston North, New Zealand
| | - J R Mickelson
- Department of Veterinary and Biomedical Sciences, 301 Veterinary Science Building, 1971 Commonwealth Avenue, St. Paul, 55108, United States
| | - M E McCue
- Department of Veterinary Population Medicine, 225 Veterinary Medical Center, 1365 Gortner Avenue, St. Paul, MN, 55108, United States
| |
Collapse
|
9
|
Norton EM, Schultz NE, Rendahl AK, Mcfarlane D, Geor RJ, Mickelson JR, McCue ME. Heritability of metabolic traits associated with equine metabolic syndrome in Welsh ponies and Morgan horses. Equine Vet J 2018; 51:475-480. [DOI: 10.1111/evj.13053] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 11/19/2018] [Indexed: 12/29/2022]
Affiliation(s)
- E. M. Norton
- Veterinary Population Medicine Department 225 Veterinary Medical Center University of Minnesota St. Paul Minnesota USA
| | - N. E. Schultz
- Veterinary Population Medicine Department 225 Veterinary Medical Center University of Minnesota St. Paul Minnesota USA
| | - A. K. Rendahl
- Veterinary and Biomedical Sciences Department University of Minnesota St. Paul Minnesota USA
| | - D. Mcfarlane
- Department of Physiological Sciences Oklahoma State University Stillwater Oklahoma USA
| | - R. J. Geor
- College of Sciences Massey University Palmerston North New Zealand
| | - J. R. Mickelson
- Veterinary and Biomedical Sciences Department University of Minnesota St. Paul Minnesota USA
| | - M. E. McCue
- Veterinary Population Medicine Department 225 Veterinary Medical Center University of Minnesota St. Paul Minnesota USA
| |
Collapse
|
10
|
McCoy AM, Norton EM, Kemper AM, Beeson SK, Mickelson JR, McCue ME. SNP
‐based heritability and genetic architecture of tarsal osteochondrosis in North American Standardbred horses. Anim Genet 2018; 50:78-81. [DOI: 10.1111/age.12738] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/18/2018] [Indexed: 11/27/2022]
Affiliation(s)
- A. M. McCoy
- Department of Veterinary Clinical Medicine University of Illinois 1008 W Hazelwood Dr Urbana IL 61802USA
| | - E. M. Norton
- Veterinary Population Medicine Department University of Minnesota 225 Veterinary Medical Center, 1365 Gortner Avenue St. Paul MN 55108USA
| | - A. M. Kemper
- Department of Veterinary Clinical Medicine University of Illinois 1008 W Hazelwood Dr Urbana IL 61802USA
| | - S. K. Beeson
- Veterinary Population Medicine Department University of Minnesota 225 Veterinary Medical Center, 1365 Gortner Avenue St. Paul MN 55108USA
| | - J. R. Mickelson
- Veterinary Biological Sciences Department University of Minnesota 301 Veterinary Science Building, 1971 Commonwealth Avenue St. Paul MN 55108 USA
| | - M. E. McCue
- Veterinary Population Medicine Department University of Minnesota 225 Veterinary Medical Center, 1365 Gortner Avenue St. Paul MN 55108USA
| |
Collapse
|
11
|
Jacob SI, Geor RJ, Weber PSD, Harris PA, McCue ME. Effect of dietary carbohydrates and time of year on ACTH and cortisol concentrations in adult and aged horses. Domest Anim Endocrinol 2018; 63:15-22. [PMID: 29195115 DOI: 10.1016/j.domaniend.2017.10.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 10/11/2017] [Accepted: 10/16/2017] [Indexed: 12/26/2022]
Abstract
Diagnosis of equine pituitary pars intermedia dysfunction (PPID) remains a challenge as multiple factors (stress, exercise, and time of year) influence ACTH and cortisol concentrations. To assess endocrine status in a study designed to evaluate the effects of age and diet on glucose and insulin dynamics, we performed thyrotropin-releasing hormone (TRH) stimulation tests and overnight dexamethasone suppression tests in March, May, August, and October on 16 healthy Thoroughbred and Standardbred mares and geldings. Horses were grouped by age: adult (mean ± SD; 8.8 ± 2.9 yr; n = 8) and aged (20.6 ± 2.1 yr; n = 8). None of the horses showed clinical signs (hypertrichosis, regional adiposity, skeletal muscle atrophy, lethargy) of pituitary pars intermedia dysfunction. Horses were randomly assigned to groups of 4, blocked for age, and fed grass hay plus 4 isocaloric concentrate diets (control, starch-rich, fiber-rich, and sugar-rich) using a balanced Latin square design. Data were analyzed using a multivariable linear mixed regression model. Baseline ACTH was significantly higher in aged horses (mean ± standard error of the mean; 60.0 ± 10.7 pg/mL) adapted to the starch-rich diet compared to adult horses (15.7 ± 12.0 pg/mL) on the same diet (P = 0.017). After controlling for age and diet, baseline ACTH concentrations were significantly increased in October (57.7 ± 7.1 pg/mL) compared to March (13.2 ± 7.1 pg/mL; P < 0.001), May (12.4 ± 7.1 pg/mL; P < 0.001), and August (24.2 ± 7.1 pg/mL; P < 0.001), whereas post-TRH ACTH was higher in August (376.6 ± 57.6 pg/mL) and October (370.9 ± 57.5 pg/mL) compared to March (101.9 ± 57.3 pg/mL; P < 0.001) and May (74.5 ± 57.1 pg/mL; P < 0.001). Aged horses had significantly higher post-dexamethasone cortisol on the starch-rich diet (0.6 ± 0.1 μg/dL) compared to the sugar-rich diet (0.2 ± 0.1 μg/dL; P = 0.021). Post-dexamethasone cortisol was significantly higher in October (0.6 ± 0.1 μg/dL) compared to March (0.3 ± 0.1 μg/dL; P = 0.005), May (0.2 ± 0.1 μg/dL; P < 0.001), and August (0.3 ± 0.1 μg/dL; P = 0.004). Breed did not influence ACTH or cortisol measurements. In conclusion, in addition to age and time of year, diet is a potential confounder as animals on a starch-rich diet may be incorrectly diagnosed with pituitary pars intermedia dysfunction.
Collapse
Affiliation(s)
- S I Jacob
- Michigan State University College of Veterinary Medicine, 736 Wilson Road, East Lansing, MI 48824, USA.
| | - R J Geor
- Massey University College of Sciences, Private Bag 11222, Palmerston North 4442, New Zealand
| | - P S D Weber
- Michigan State University College of Veterinary Medicine, 736 Wilson Road, East Lansing, MI 48824, USA
| | - P A Harris
- Equine Studies Group, WALTHAM Centre for Pet Nutrition, Freeby Lane, Leicestershire, UK
| | - M E McCue
- University of Minnesota College of Veterinary Medicine, 1365 Gortner Avenue, St. Paul, MN 55108, USA
| |
Collapse
|
12
|
Jacob SI, Geor RJ, Weber PSD, Harris PA, McCue ME. Effect of age and dietary carbohydrate profiles on glucose and insulin dynamics in horses. Equine Vet J 2017; 50:249-254. [PMID: 28833406 DOI: 10.1111/evj.12745] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 08/10/2017] [Indexed: 12/29/2022]
Abstract
BACKGROUND Glucose and insulin dynamics may be different in adult and aged horses. OBJECTIVES To determine the effects of age and dietary carbohydrates on glucose and insulin dynamics in healthy horses. STUDY DESIGN Balanced Latin square with four isocaloric diets: CONTROL (hay plus restricted-starch-and-sugar fortified pellets), STARCH (control plus kibbled corn), FIBER (control plus unmolassed sugar beet pulp/soybean hull pellets) and SUGAR (control plus dextrose powder). METHODS A total of 16 healthy Thoroughbreds and Standardbreds divided into two age groups: ADULT (8.8 ± 2.9 years; n = 8) and AGED (20.6 ± 2.1 years; n = 8). Following dietary adaptation, horses underwent an insulin-modified frequently sampled intravenous glucose tolerance test (FSIGTT), modified oral sugar test (OST) and dietary meal challenge. Outcome variables included: insulin sensitivity (SI), disposition index (DI), glucose effectiveness (Sg) and acute insulin response to glucose (AIRg) from the FSIGTT; peak glucose, peak insulin, time to peak, area under the curve for glucose (AUCg) and insulin (AUCi) from the OST and dietary meal challenge. Data were analyzed using multivariable linear mixed regression modelling. RESULTS AIRg was higher in AGED (mean [95% confidence interval]; 582.0 [455.0-709.0]) vs. ADULT (358.0 [224.0-491.0]; P = 0.03). ADULT and AGED horses had a higher SI on STARCH (adult: 3.3 [2.3-4.2]; aged: 2.8 [1.9-3.7]) and SUGAR (adult: 3.4 [2.5-4.3]; aged: 4.0 [3.1-4.9]) diets compared with CONTROL (adult: 2.0 [1.1-2.9], P = 0.029 (starch), P = 0.009 (sugar); aged: 1.4 [0.5-2.2], P = 0.009 (starch), P < 0.001 (sugar)). Feeding a STARCH (adult: 21581.0 [15029.0-28133.0]; aged: 35205.0 [29194.0-41216.0]) or SUGAR (adult: 26050.0 [19885.0-32215.0]; aged: 25720.0 [19770.0-31670.0]) meal resulted in postprandial hyperinsulinaemia (AUCi). MAIN LIMITATIONS Study cohort contained two insulin-sensitive breeds and no insulin-resistant breeds. CONCLUSIONS Age and diet should be considered when evaluating glucose and insulin dynamics.
Collapse
Affiliation(s)
- S I Jacob
- Michigan State University College of Veterinary Medicine, East Lansing, Michigan, USA
| | - R J Geor
- Massey University College of Sciences, Palmerston North, New Zealand
| | - P S D Weber
- Michigan State University College of Veterinary Medicine, East Lansing, Michigan, USA
| | - P A Harris
- Equine Studies Group, WALTHAM Centre for Pet Nutrition, Leicestershire, UK
| | - M E McCue
- University of Minnesota College of Veterinary Medicine, St. Paul, Minnesota, USA
| |
Collapse
|
13
|
Maile CA, Hingst JR, Mahalingan KK, O'Reilly AO, Cleasby ME, Mickelson JR, McCue ME, Anderson SM, Hurley TD, Wojtaszewski JFP, Piercy RJ. A highly prevalent equine glycogen storage disease is explained by constitutive activation of a mutant glycogen synthase. Biochim Biophys Acta Gen Subj 2016; 1861:3388-3398. [PMID: 27592162 DOI: 10.1016/j.bbagen.2016.08.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 08/15/2016] [Accepted: 08/30/2016] [Indexed: 01/16/2023]
Abstract
BACKGROUND Equine type 1 polysaccharide storage myopathy (PSSM1) is associated with a missense mutation (R309H) in the glycogen synthase (GYS1) gene, enhanced glycogen synthase (GS) activity and excessive glycogen and amylopectate inclusions in muscle. METHODS Equine muscle biochemical and recombinant enzyme kinetic assays in vitro and homology modelling in silico, were used to investigate the hypothesis that higher GS activity in affected horse muscle is caused by higher GS expression, dysregulation, or constitutive activation via a conformational change. RESULTS PSSM1-affected horse muscle had significantly higher glycogen content than control horse muscle despite no difference in GS expression. GS activity was significantly higher in muscle from homozygous mutants than from heterozygote and control horses, in the absence and presence of the allosteric regulator, glucose 6 phosphate (G6P). Muscle from homozygous mutant horses also had significantly increased GS phosphorylation at sites 2+2a and significantly higher AMPKα1 (an upstream kinase) expression than controls, likely reflecting a physiological attempt to reduce GS enzyme activity. Recombinant mutant GS was highly active with a considerably lower Km for UDP-glucose, in the presence and absence of G6P, when compared to wild type GS, and despite its phosphorylation. CONCLUSIONS Elevated activity of the mutant enzyme is associated with ineffective regulation via phosphorylation rendering it constitutively active. Modelling suggested that the mutation disrupts a salt bridge that normally stabilises the basal state, shifting the equilibrium to the enzyme's active state. GENERAL SIGNIFICANCE This study explains the gain of function pathogenesis in this highly prevalent polyglucosan myopathy.
Collapse
Affiliation(s)
- C A Maile
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Sciences and Services, Royal Veterinary College, London, UK
| | - J R Hingst
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark
| | - K K Mahalingan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, USA
| | - A O O'Reilly
- School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool, UK
| | - M E Cleasby
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, UK
| | - J R Mickelson
- Veterinary Biomedical Sciences Department, University of Minnesota, St. Paul, MN, USA
| | - M E McCue
- Veterinary Population Medicine Department, University of Minnesota, St. Paul, MN, USA
| | - S M Anderson
- Veterinary Population Medicine Department, University of Minnesota, St. Paul, MN, USA
| | - T D Hurley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, USA
| | - J F P Wojtaszewski
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark
| | - R J Piercy
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Sciences and Services, Royal Veterinary College, London, UK.
| |
Collapse
|
14
|
Lykkjen S, Dolvik NI, McCue ME, Rendahl AK, Mickelson JR, Roed KH. Genome-wide association analysis of osteochondrosis of the tibiotarsal joint in Norwegian Standardbred trotters. Anim Genet 2015; 41 Suppl 2:111-20. [PMID: 21070284 DOI: 10.1111/j.1365-2052.2010.02117.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Osteochondrosis (OC), a disturbance in the process of endochondral ossification, is by far the most important equine developmental orthopaedic disease and is also common in other domestic animals and humans. The purpose of this study was to identify quantitative trait loci (QTL) associated with osteochondrosis dissecans (OCD) at the intermediate ridge of the distal tibia in Norwegian Standardbred (SB) using the Illumina Equine SNP50 BeadChip whole-genome single-nucleotide polymorphism (SNP) assay. Radiographic data and blood samples were obtained from 464 SB yearlings. Based on the radiographic examination, 162 horses were selected for genotyping; 80 of these were cases with an OCD at the intermediate ridge of the distal tibia, and 82 were controls without any developmental lesions in the joints examined. Genotyped horses descended from 22 sires, and the number of horses in each half-sib group ranged from 3 to 14. The population structure necessitated statistical correction for stratification. When conducting a case-control genome-wide association study (GWAS), mixed-model analyses displayed regions on chromosomes (Equus callabus chromosome - ECA) 5, 10, 27 and 28 that showed moderate evidence of association (P ≤ 5 × 10(-5); this P-value is uncorrected i.e. not adjusted for multiple comparisons) with OCD in the tibiotarsal joint. Two SNPs on ECA10 represent the most significant hits (uncorrected P=1.19 × 10(-5) in the mixed-model). In the basic association (chi-square) test, these SNPs achieved statistical significance with the Bonferroni correction (P=0.038) and were close in the permuted logistic regression test (P=0.054). Putative QTL on ECA 5, 10, 27 and 28 represent interesting areas for future research, validation studies and fine mapping of candidate regions. Results presented here represent the first GWAS of OC in horses using the recently released Illumina Equine SNP50 BeadChip.
Collapse
Affiliation(s)
- S Lykkjen
- The Norwegian School of Veterinary Science, Department of Basic Sciences and Aquatic Medicine, Post-box 8146 Dep., N-0033 Oslo, Norway.
| | | | | | | | | | | |
Collapse
|
15
|
McCoy AM, Ralston SL, McCue ME. Short- and long-term racing performance of Standardbred pacers and trotters after early surgical intervention for tarsal osteochondrosis. Equine Vet J 2014; 47:438-44. [PMID: 24819047 DOI: 10.1111/evj.12297] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 04/27/2014] [Indexed: 11/29/2022]
Abstract
REASONS FOR PERFORMING STUDY Osteochondrosis (OC) is commonly diagnosed in young Standardbred racehorses but its effect on performance when surgically treated at a young age is still incompletely understood. This is especially true for Standardbred pacers, which are underrepresented in the existing literature. OBJECTIVE To characterise the short- (2-year-old) and long-term (through 5-year-old) racing performance in Standardbred pacers and trotters after early surgical intervention (<17 months of age) for tarsal OC. STUDY DESIGN Retrospective clinical study. METHODS The study population consisted of related, age-matched Standardbred racehorses (n = 278; 151 pacers, 127 trotters) with (n = 133) or without (n = 145) one or more tarsal OC lesions. All OC-affected horses were treated surgically prior to being sold as yearlings. Data obtained from publicly available race records for each horse included starts, wins, finishes in the top 3 (win, place or show), earnings and fastest time. Comparisons between OC-affected and unaffected horses were made for the entire population and within gaits. A smaller related population (n = 94) had these performance measures evaluated for their 2-5-year-old racing seasons. RESULTS Osteochondrosis status was associated with few performance measures. Trotters were at higher risk for lesions of the medial malleolus but lower risk for lesions of the distal intermediate ridge of the tibia than were pacers. Horses with bilateral OC lesions and lateral trochlear ridge (LTR) lesions started fewer races at 2 years of age than those with unilateral lesions or without LTR lesions. CONCLUSIONS Osteochondrosis seemed to have minimal effect on racing performance in this cohort, although horses with bilateral and LTR lesions started fewer races at 2 years. There was evidence for different distribution of OC lesions among pacers and trotters, which should be explored further. Standardbreds undergoing early removal of tarsal OC lesions can be expected to perform equivalently to their unaffected counterparts.
Collapse
Affiliation(s)
- A M McCoy
- Veterinary Population Medicine Department, University of Minnesota, St. Paul, USA
| | - S L Ralston
- Department of Animal Science, Rutgers, The State University of New Jersey, New Brunswick, USA
| | - M E McCue
- Veterinary Population Medicine Department, University of Minnesota, St. Paul, USA
| |
Collapse
|
16
|
Martinson KL, Coleman RC, Rendahl AK, Fang Z, McCue ME. Estimation of body weight and development of a body weight score for adult equids using morphometric measurements. J Anim Sci 2014; 92:2230-8. [PMID: 24663191 DOI: 10.2527/jas.2013-6689] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Excessive BW has become a major health issue in the equine (Equus caballus) industry. The objectives were to determine if the addition of neck circumference and height improved existing BW estimation equations, to develop an equation for estimation of ideal BW, and to develop a method for assessing the likelihood of being overweight in adult equids. Six hundred and twenty-nine adult horses and ponies who met the following criteria were measured and weighed at 2 horse shows in September 2011 in Minnesota: age ≥ 3 yr, height ≥ 112 cm, and nonpregnant. Personnel assessed BCS on a scale of 1 to 9 and measured wither height at the third thoracic vertebra, body length from the point of shoulder to the point of the buttock, neck and girth circumference, and weight using a portable livestock scale. Individuals were grouped into breed types on the basis of existing knowledge and were confirmed with multivariate ANOVA analysis of morphometric measurements. Equations for estimated and ideal BW were developed using linear regression modeling. For estimated BW, the model was fit using all individuals and all morphometric measurements. For ideal BW, the model was fit using individuals with a BCS of 5; breed type, height, and body length were considered as these measurements are not affected by adiposity. A BW score to assess the likelihood of being overweight was developed by fitting a proportional odds logistic regression model on BCS using the difference between ideal and estimated BW, the neck to height ratio, and the girth to height ratio as predictors; this score was then standardized using the data from individuals with a BCS of 5. Breed types included Arabian, stock, and pony. Mean (± SD) BCS was 5.6 ± 0.9. BW (kg) was estimated by taking [girth (cm)(1.48)6 × length (cm)(0.554) × height (cm)(0.599) × neck (cm)(0.173)]/3,596, 3,606, and 3,441 for Arabians, ponies, and stock horses, respectively (R(2) = 0.92; mean-squared error (MSE) = 22 kg). Ideal BW (kg) was estimated by taking [length (cm) × 2.8] + [height (cm) × 4.2] - 611, 606, and 577 for Arabians, ponies, and stock horses, respectively (R(2) = 0.86; MSE = 24). Equids with a BCS of ≥ 7 had a greater likelihood of being overweight, and the model suggested cutoffs at the 48th and 83rd percentiles for underweight and overweight individuals, respectively. Morphometric measurements were successfully used to develop equid BW-related equations.
Collapse
Affiliation(s)
- K L Martinson
- Department of Animal Science, University of Minnesota, St. Paul 55108
| | | | | | | | | |
Collapse
|
17
|
Fritz KL, Kaese HJ, Valberg SJ, Hendrickson JA, Rendahl AK, Bellone RR, Dynes KM, Wagner ML, Lucio MA, Cuomo FM, Brinkmeyer-Langford CL, Skow LC, Mickelson JR, Rutherford MS, McCue ME. Genetic risk factors for insidious equine recurrent uveitis in Appaloosa horses. Anim Genet 2014; 45:392-9. [PMID: 24467435 DOI: 10.1111/age.12129] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/12/2013] [Indexed: 11/29/2022]
Abstract
Appaloosa horses are predisposed to equine recurrent uveitis (ERU), an immune-mediated disease characterized by recurring inflammation of the uveal tract in the eye, which is the leading cause of blindness in horses. Nine genetic markers from the ECA1 region responsible for the spotted coat color of Appaloosa horses, and 13 microsatellites spanning the equine major histocompatibility complex (ELA) on ECA20, were evaluated for association with ERU in a group of 53 Appaloosa ERU cases and 43 healthy Appaloosa controls. Three markers were significantly associated (corrected P-value <0.05): a SNP within intron 11 of the TRPM1 gene on ECA1, an ELA class I microsatellite located near the boundary of the ELA class III and class II regions and an ELA class II microsatellite located in intron 1 of the DRA gene. Association between these three genetic markers and the ERU phenotype was confirmed in a second population of 24 insidious ERU Appaloosa cases and 16 Appaloosa controls. The relative odds of being an ERU case for each allele of these three markers were estimated by fitting a logistic mixed model with each of the associated markers independently and with all three markers simultaneously. The risk model using these markers classified ~80% of ERU cases and 75% of controls in the second population as moderate or high risk, and low risk respectively. Future studies to refine the associations at ECA1 and ELA loci and identify functional variants could uncover alleles conferring susceptibility to ERU in Appaloosa horses.
Collapse
Affiliation(s)
- K L Fritz
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, 55108, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Affiliation(s)
- A M McCoy
- Veterinary Population Medicine Department, University of Minnesota, St. Paul, MN, 55108, USA
| | | |
Collapse
|
19
|
Teixeira RBC, Rendahl AK, Anderson SM, Mickelson JR, Sigler D, Buchanan BR, Coleman RJ, McCue ME. Coat color genotypes and risk and severity of melanoma in gray quarter horses. J Vet Intern Med 2013; 27:1201-8. [PMID: 23875712 DOI: 10.1111/jvim.12133] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 04/08/2013] [Accepted: 05/22/2013] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Both graying and melanoma formation in horses have recently been linked to a duplication in the STX17 gene. This duplication, as well as a mutation in the ASIP gene that increases MC1R pathway signaling, affects melanoma risk and severity in gray horses. OBJECTIVE To determine if melanoma susceptibility in gray Quarter Horses (QH) is lower than gray horses from other breeds because of decreased MC1R signaling resulting from a high incidence of the MC1R chestnut coat color allele in the QH population. ANIMALS A total of 335 gray QH with and without dermal melanomas. METHODS Blood or hair root samples were collected from all horses for DNA extraction and genotyping for STX17, ASIP, and MC1R genotypes. Age, sex, and external melanoma presence and grade were recorded. The effect of age and genotype on melanoma presence and severity was evaluated by candidate gene association. RESULTS Melanoma prevalence (16%) and grade (0.35) in this QH cohort was lower than that reported in other breeds. Age was significantly associated with melanoma prevalence (P = 5.28 × 10(-11)) and severity (P = 2.2 × 10(-13)). No significant effect of MC1R genotype on melanoma prevalence or severity was identified. An effect of ASIP genotype on melanoma risk was not detected. Low STX17 homozygosity precluded evaluation of the gray allele effect. CONCLUSION AND CLINICAL IMPORTANCE Melanoma prevalence and severity is lower in this population of gray QH than what is reported in other breeds. This could be because of the infrequent STX17 homozygosity, a mitigating effect of the MC1R mutation on ASIP potentiation of melanoma, other genes in the MC1R signaling pathway, or differences in breed genetic background.
Collapse
Affiliation(s)
- R B C Teixeira
- Veterinary Population Medicine, University of Minnesota, St Paul, MN
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Lykkjen S, Dolvik NI, McCue ME, Rendahl AK, Mickelson JR, Røed KH. Equine developmental orthopaedic diseases--a genome-wide association study of first phalanx plantar osteochondral fragments in Standardbred trotters. Anim Genet 2013; 44:766-9. [PMID: 23742657 DOI: 10.1111/age.12064] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2013] [Indexed: 11/30/2022]
Abstract
Palmar/plantar osteochondral fragments (POF) in fetlock joints commonly affect and influence the athletic performance of horses. In this study, we used the Equine SNP50 BeadChip® to perform a genome-wide association study of metatarsophalangeal POF in 176 Norwegian Standardbred trotter yearlings. Putative quantitative trait loci (QTL) for medial and/or lateral POF, and medial POF only were identified on ECA1, 2, 7, 9 and 31, whereas for lateral POF, only on ECA7, 11, 27 and X. The moderate number of QTL evidences a complex inheritance and suggests various genes controlling POF development in medial and lateral locations.
Collapse
Affiliation(s)
- S Lykkjen
- Department of Basic Sciences and Aquatic Medicine, The Norwegian School of Veterinary Science, Post-box 8146 Dep., N-0033, Oslo, Norway; Department of Companion Animal Clinical Sciences, Section for Equine Medicine and Surgery, The Norwegian School of Veterinary Science, Post-box 8146 Dep, N-0033, Oslo, Norway
| | | | | | | | | | | |
Collapse
|
21
|
Fritz KL, McCue ME, Valberg SJ, Rendahl AK, Mickelson JR. Genetic mapping of recurrent exertional rhabdomyolysis in a population of North American Thoroughbreds. Anim Genet 2012; 43:730-8. [PMID: 22497487 DOI: 10.1111/j.1365-2052.2012.02351.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2012] [Indexed: 11/30/2022]
Abstract
Recurrent exertional rhabdomyolysis is a heritable disorder that results in painful skeletal muscle cramping with exercise in up to 10% of all Thoroughbred racehorses. Here, we report a genome-wide association study with 48 282 SNPs analyzed among 48 case and 37 control Thoroughbreds. The most significant SNPs spanned approximately 13 Mb on ECA16, and the P-value of the most significant SNP after correcting for population structure was 8.0 × 10(-6) . This region on ECA16 was further evaluated by genotyping 247 SNPs in both the initial population and a second population of 34 case and 98 control Thoroughbreds. Several SNPs across the 13-Mb region on ECA16 showed significance when each population was analyzed separately; however, the exact positions of the most significant SNPs within this region on ECA16 varied between populations. This variability in location may be attributed to lack of power owing to insufficient sample sizes within each population individually, or to the relative distribution of long, conserved haplotypes, characteristic of the Thoroughbred breed. Future genome-wide association studies with additional horses would likely improve the power to resolve casual loci located on ECA16 and increase the likelihood of detecting any additional loci on other chromosomes contributing to disease susceptibility.
Collapse
Affiliation(s)
- K L Fritz
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN 55108, USA.
| | | | | | | | | |
Collapse
|
22
|
Baird JD, Valberg SJ, Anderson SM, McCue ME, Mickelson JR. Presence of the glycogen synthase 1 (GYS1
) mutation causing type 1 polysaccharide storage myopathy in continental European draught horse breeds. Vet Rec 2010; 167:781-4. [DOI: 10.1136/vr.c3447] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- J. D. Baird
- Department of Clinical Studies; Ontario Veterinary College; University of Guelph; Guelph Ontario N1G 2W1 Canada
| | - S. J. Valberg
- Department of Veterinary Population Medicine; College of Veterinary Medicine; University of Minnesota; St Paul MN 55108 USA
| | - S. M. Anderson
- Department of Veterinary and Biomedical Sciences; College of Veterinary Medicine; University of Minnesota; St Paul MN 55108 USA
| | - M. E. McCue
- Department of Veterinary Population Medicine; College of Veterinary Medicine; University of Minnesota; St Paul MN 55108 USA
| | - J. R. Mickelson
- Department of Veterinary and Biomedical Sciences; College of Veterinary Medicine; University of Minnesota; St Paul MN 55108 USA
| |
Collapse
|
23
|
McCue ME, Anderson SM, Valberg SJ, Piercy RJ, Barakzai SZ, Binns MM, Distl O, Penedo MCT, Wagner ML, Mickelson JR. Estimated prevalence of the Type 1 Polysaccharide Storage Myopathy mutation in selected North American and European breeds. Anim Genet 2010; 41 Suppl 2:145-9. [DOI: 10.1111/j.1365-2052.2010.02124.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
24
|
Abstract
REASONS FOR PERFORMING STUDY Controversy exists as to the prevalence of polysaccharide storage myopathy (PSSM) in breeds of horses and its impact on performance. OBJECTIVES To determine 1) the prevalence of PSSM in horses that presented with a neuromuscular disorder, as well as breed, sex and age distributions and clinical signs 2) effect of diagnostic criteria on prevalence, breed distribution and age of horses diagnosed with PSSM. METHODS Fresh frozen biopsies (n = 1426) submitted to the Neuromuscular Diagnostic Laboratory at the University of Minnesota were searched to identify horses diagnosed with PSSM. Horses with and without histological evidence of PSSM were compared. Biopsies were classified as Grade 1, containing aggregates of granular glycogen or Grade 2, containing periodic acid Schiff's (PAS) positive inclusions, traditionally resistant to amylase digestion. RESULTS Horses (n = 572 : 40.1%) were identified with PSSM, of which 62.9% were Quarter Horse related breeds (QHR), 11.5% Draught breeds (DB) and 8.9% Warmblood breeds (WB). Exertional rhabdomyolysis was more prevalent in QHR than DB and WB, whereas QHR were less likely to have muscle atrophy compared to DB. QHR were less likely to have gait abnormalities than DB and WB. The highest within breed prevalence of PSSM was in DB at 63/116, WB 58/111 and QHR 360/753. Exclusion of Grade 1 criteria decreased the overall prevalence of PSSM to 21.7% of biopsy submissions, and decreased the within breed prevalence in each breed category. The within breed prevalence decreased most substantially in the breeds less commonly diagnosed with PSSM, Thoroughbreds (4.5%) and Arabians (2.5%). CONCLUSION PSSM is a common cause of neuromuscular disease in QHR, DB and WB related breeds. Inclusion of granular glycogen as the sole diagnostic criterion may increase the sensitivity of this diagnostic test, but conversely it may decrease the specificity of the diagnosis resulting in the inclusion of horses of Thoroughbred, Arabian and other breeds. POTENTIAL RELEVANCE PSSM is an important differential diagnosis for QHR, WB and DB presenting with signs of rhabdomyolysis, gait abnormalities and muscle atrophy.
Collapse
Affiliation(s)
- M E McCue
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, 1365 Gortner Avenue, St. Paul, Minnesota 55108, USA
| | | | | |
Collapse
|
25
|
Stanley RL, McCue ME, Valberg SJ, Mickelson JR, Mayhew IG, McGowan C, Hahn CN, Patterson-Kane JC, Piercy RJ. A glycogen synthase 1 mutation associated with equine polysaccharide storage myopathy and exertional rhabdomyolysis occurs in a variety of UK breeds. Equine Vet J 2009; 41:597-601. [PMID: 19803057 DOI: 10.2746/042516409x407611] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
REASONS FOR PERFORMING STUDY A glycogen synthase (GYS1) mutation has been described in horses with histopathological evidence of polysaccharide storage myopathy (PSSM) in the USA. It is unknown whether the same mutation is present in horses from the UK. OBJECTIVES To determine whether the GYS1 mutation occurs in UK horses with histopathological evidence of PSSM and exertional rhabdomyolysis. HYPOTHESIS The R309H GYS1 mutation is present in a variety of UK horse breeds and that the mutation is commonly associated with exertional rhabdomyolysis. METHODS DNA was extracted from 47 muscle or blood samples from UK horses with histories of exertional rhabdomyolysis in which muscle biopsy diagnosis had been pursued. The proportions of GYS1 mutation positive cases were compared among histopathologically defined groups. In addition, breeds that carried the GYS1 mutation were identified from a total of 37 grade 2 (amylase-resistant) PSSM cases. RESULTS Of 47 horses with exertional rhabdomyolysis in which a muscle biopsy diagnosis was pursued, 10 (21%) carried the GYS1 mutation. The mutation was only found in horses with grade 2 PSSM (i.e. not in horses with normal, idiopathic myopathy or grade 1 PSSM biopsy samples). In total, the GYS1 mutation was found in 24/37 (65%) of grade 2 PSSM cases. A variety of breeds, including Quarter Horse, Appaloosa, Warmblood, Connemara-cross, Cob, Polo Pony and Thoroughbred cross carried the mutation. CONCLUSIONS The GYS1 mutation is an important cause of exertional rhabdomyolysis of UK horse breeds but does not account for all forms of PSSM. POTENTIAL RELEVANCE Genotyping is recommended in cases of exertional rhabdomyolysis, prior to or in combination with, muscle biopsy. However a significant proportion of horses with histopathological evidence of PSSM and/or exertional rhabdomyolysis have different diseases.
Collapse
Affiliation(s)
- R L Stanley
- Comparative Neuromuscular Diseases Laboratory, Department of Veterinary Clinical Sciences, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
26
|
McCue ME, Armién AG, Lucio M, Mickelson JR, Valberg SJ. Comparative Skeletal Muscle Histopathologic and Ultrastructural Features in Two Forms of Polysaccharide Storage Myopathy in Horses. Vet Pathol 2009; 46:1281-91. [DOI: 10.1354/vp.08-vp-0177-m-fl] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Polysaccharide storage myopathy (PSSM) has been found in more than 35 different horse breeds through identification of abnormal storage of polysaccharide in muscle biopsies. A dominant mutation in the glycogen synthase 1 gene ( GYS1) accounts for a substantial proportion of PSSM cases in at least 17 breeds, including Quarter Horses, but some horses diagnosed with PSSM by muscle histopathologic analysis are negative for the mutation. We hypothesized that a second distinct form of glycogen storage disease exists in GYS1 -negative horses with PSSM. The objectives of this study were to compare the histopathologic features, ultrastructure of polysaccharide, signalment, history, and presenting complaints of GYS1 -negative Quarter Horses and related breeds with PSSM to those of GYS1 -positive horses with PSSM. The total histopathologic score in frozen sections of skeletal muscle stained with hematoxylin and eosin, periodic acid Schiff (PAS) and amylase-PAS stains from 53 GYS1-negative horses did not differ from that of 52 GYS1 -positive horses. Abnormal polysaccharide was fine granular or homogenous in appearance (49/53; 92%), often amylase-sensitive (28/53; 53%), more commonly located under the sarcolemma, and consisting of β glycogen particles in GYS1 -negative horses. However, in GYS1 -positive horses, abnormal polysaccharide was usually coarse granular (50/52; 96%), amylase-resistant (51/52; 98%), more commonly cytoplasmic, and consisting of β glycogen particles or, in some myofibers, filamentous material surrounded by β glycogen particles. Retrospective analysis found that GYS1 -negative horses ( n = 43) were younger at presentation (4.9 ± 0.6 years vs. 6.7 ± 0.3 years for GYS1 -positive horses) and were more likely to be intact males than GYS1 -positive horses ( n = 160). We concluded that 2 forms of PSSM exist and often have distinctive abnormal polysaccharide. However, because evaluation of the histologic appearance of polysaccharide can be subjective and affected by age, the gold standard for diagnosis of PSSM at present would appear to be testing for the GYS1 mutation followed by evaluating muscle biopsy for characteristic abnormal polysaccharide in those horses that are negative for the mutation.
Collapse
Affiliation(s)
- M. E. McCue
- Department of Veterinary Population Medicine, University of Minnesota College of Veterinary Medicine
| | - A. G. Armién
- Department of Veterinary Population Medicine, University of Minnesota College of Veterinary Medicine
| | - M. Lucio
- Department of Veterinary Population Medicine, University of Minnesota College of Veterinary Medicine
| | - J. R. Mickelson
- Department of Veterinary Biosciences, University of Minnesota College of Veterinary Medicine
| | - S. J. Valberg
- Department of Veterinary Population Medicine, University of Minnesota College of Veterinary Medicine
| |
Collapse
|
27
|
McCue ME, Valberg SJ, Jackson M, Borgia L, Lucio M, Mickelson JR. Polysaccharide storage myopathy phenotype in quarter horse-related breeds is modified by the presence of an RYR1 mutation. Neuromuscul Disord 2008; 19:37-43. [PMID: 19056269 DOI: 10.1016/j.nmd.2008.10.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Revised: 08/25/2008] [Accepted: 10/05/2008] [Indexed: 10/21/2022]
Abstract
In this study we examined a family of Quarter Horses with Polysaccharide Storage Myopathy (PSSM) with a dominant mutation in the skeletal muscle glycogen synthase (GYS1) gene. A subset of horses within this family had a more severe and occasionally fatal PSSM phenotype. The purpose of this study was to identify a modifying gene(s) for the severe clinical phenotype. A genetic association analysis was used to identify RYR1 as a candidate modifying gene. A rare, known equine RYR1 mutation, associated with malignant hyperthermia (MH), was found to segregate in this GYS1 PSSM family. Retrospective analysis of patient records (n=179) demonstrated that horses with both the GYS1 and RYR1 mutations had a more severe clinical phenotype than horses with the GYS1 mutation alone. A treadmill trial (n=8) showed that serum creatine kinase activity was higher and exercise intolerance greater in horses with both mutations compared to the GYS1 mutation alone.
Collapse
Affiliation(s)
- M E McCue
- Department of Veterinary Population Medicine, University of Minnesota College of Veterinary Medicine, 225 VMC, 1365 Gortner Avenue, St. Paul, MN 55108, USA.
| | | | | | | | | | | |
Collapse
|
28
|
Herszberg B, McCue ME, Larcher T, Mata X, Vaiman A, Chaffaux S, Chérel Y, Valberg SJ, Mickelson JR, Guérin G. A GYS1 gene mutation is highly associated with polysaccharide storage myopathy in Cob Normand draught horses. Anim Genet 2008; 40:94-6. [PMID: 18822097 DOI: 10.1111/j.1365-2052.2008.01778.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Glycogen storage diseases or glycogenoses are inherited diseases caused by abnormalities of enzymes that regulate the synthesis or degradation of glycogen. Deleterious mutations in many genes of the glyco(geno)lytic or the glycogenesis pathways can potentially cause a glycogenosis, and currently mutations in fourteen different genes are known to cause animal or human glycogenoses, resulting in myopathies and/or hepatic disorders. The genetic bases of two forms of glycogenosis are currently known in horses. A fatal neonatal polysystemic type IV glycogenosis, inherited recessively in affected Quarter Horse foals, is due to a mutation in the glycogen branching enzyme gene (GBE1). A second type of glycogenosis, termed polysaccharide storage myopathy (PSSM), is observed in adult Quarter Horses and other breeds. A severe form of PSSM also occurs in draught horses. A mutation in the skeletal muscle glycogen synthase gene (GYS1) was recently reported to be highly associated with PSSM in Quarter Horses and Belgian draught horses. This GYS1 point mutation appears to cause a gain-of-function of the enzyme and to result in the accumulation of a glycogen-like, less-branched polysaccharide in skeletal muscle. It is inherited as a dominant trait. The aim of this work was to test for possible associations between genetic polymorphisms in four candidate genes of the glycogen pathway or the GYS1 mutation in Cob Normand draught horses diagnosed with PSSM by muscle biopsy.
Collapse
Affiliation(s)
- B Herszberg
- INRA, UR339, Laboratoire de Génétique Biochimique et de Cytogénétique, Centre de Recherches de Jouy, 78350 Jouy-en-Josas, France.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
McCue ME, Valberg SJ, Lucio M, Mickelson JR. Glycogen synthase 1 (GYS1) mutation in diverse breeds with polysaccharide storage myopathy. J Vet Intern Med 2008; 22:1228-33. [PMID: 18691366 DOI: 10.1111/j.1939-1676.2008.0167.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND A missense mutation in the GYS1 gene was recently described in horses with polysaccharide storage myopathy (PSSM). OBJECTIVES The first objective was to determine the prevalence of the GYS1 mutation in horses with PSSM from diverse breeds. The second objective was to determine if the prevalence of the GYS1 mutation differed between horses diagnosed with PSSM based on grade 1 (typically amylase-sensitive) or grade 2 (typically amylase-resistant) polysaccharide. ANIMALS Eight hundred and thirty-one PSSM horses from 36 breeds. PROCEDURES Horses with PSSM diagnosed by histopathology of skeletal muscle biopsy samples were identified from the Neuromuscular Disease Laboratory database. Eight hundred and thirty-one cases had blood or tissue that was available for DNA isolation; these 831 cases were genotyped for the GYS1 mutation by restriction fragment length polymorphism. RESULTS The PSSM mutation was identified in horses from 17 different breeds. The prevalence of the GYS1 mutation in PSSM horses was high in Draft- (87%) and Quarter Horse-related breeds (72%) and lower in Warmbloods (18%) and other light horse breeds (24%), when diagnosis was based on grade 2 diagnostic criteria. Overall, the PSSM mutation was present in 16% of grade 1 and 70% of grade 2 PSSM horses. CONCLUSIONS AND CLINICAL IMPORTANCE GYS1 mutation causes PSSM in diverse breeds and is the predominant form of PSSM in Draft- and Quarter Horse-related breeds. False-positive diagnosis, as well as the possibility of a second glycogenosis in horses with neuromuscular disease (type 2 PSSM), might explain the absence of the GYS1 mutation in horses diagnosed with excessive glycogen accumulation in muscle.
Collapse
Affiliation(s)
- M E McCue
- Department of Veterinary Population Medicine, University of Minnesota College of Veterinary Medicine, St Paul, MN, USA.
| | | | | | | |
Collapse
|