OMIA 002330-9796 : Myopathy, myofibrillar in Equus caballus

Possibly relevant human trait(s) and/or gene(s)s (MIM numbers): 603689 (trait) , 601419 (trait) , 617114 (trait) , 609200 (trait) , 609524 (trait) , 619040 (trait) , 609452 (trait) , 612954 (trait) , 613869 (trait) , 608810 (trait) , 617258 (trait) , 619178 (trait)

Mendelian trait/disorder: unknown

Considered a defect: yes

Species-specific symbol: MFM

Inheritance: Williams et al. (2020): ".. a potential familial basis for MFM has been suggested by the presence of desmin aggregates in a 3‐generation family of WB [Valberg et al. 2017].

Molecular basis: Williams et al. (2020): "Variants identified in MFM candidate genes, including two coding variants offered as commercial MFM equine genetic tests, did not associate with the WB MFM phenotype."

Clinical features: Williams et al. (2020): "Clinical signs associated with MFM WB are usually apparent by 11 years of age and include exercise intolerance, a reluctance to move forward under saddle and a mild lameness not attributable to an underlying orthopaedic cause."

Pathology: Valberg et al. (2017): " Abnormal aggregates of the cytoskeletal protein desmin were found in up to 120 type 2a and a few type 2x myofibres of MFM cases. Desmin positive fibres did not stain for developmental myosin, α actinin or dystrophin. Scores for internalised myonuclei (score MFM 0.83 ± 0.67, controls 0.22 ± 0.45), anguloid atrophy (MFM 0.95 ± 0.55, controls 0.31 ± 0.37) and total myopathic scores (MFM 5.85 ± 2.10, controls 1.41 ± 2.17) were significantly higher in MFM cases vs. controls. Focal Z disc degeneration, myofibrillar disruption and accumulation of irregular granular material was evident in MFM cases. Muscle glycogen concentrations were similar between MFM cases and controls. In the Warmblood family, desmin positive aggregates were found in myofibres of the founding dam and in horses from two subsequent generations."

Breed: Arabian.

References


Note: the references are listed in reverse chronological order (from the most recent year to the earliest year), and alphabetically by first author within a year.
2022 Valberg, S.J., Henry, M.L., Herrick, K.L., Velez-Irizarry, D., Finno, C.J., Petersen, J.L. :
Absence of myofibrillar myopathy in Quarter Horses with a histopathological diagnosis of type 2 polysaccharide storage myopathy and lack of association with commercial genetic tests. Equine Vet J :, 2022. Pubmed reference: 35288976. DOI: 10.1111/evj.13574.
2021 Williams, Z.J., Velez-Irizarry, D., Petersen, J.L., Ochala, J., Finno, C.J., Valberg, S.J. :
Candidate gene expression and coding sequence variants in Warmblood horses with myofibrillar myopathy. Equine Vet J 53:306-315, 2021. Pubmed reference: 32453872. DOI: 10.1111/evj.13286.
Williams, Z.J., Velez-Irizarry, D., Gardner, K., Valberg, S.J. :
Integrated proteomic and transcriptomic profiling identifies aberrant gene and protein expression in the sarcomere, mitochondrial complex I, and the extracellular matrix in Warmblood horses with myofibrillar myopathy. BMC Genomics 22:438, 2021. Pubmed reference: 34112090. DOI: 10.1186/s12864-021-07758-0.
2018 Williams, Z.J., Bertels, M., Valberg, S.J. :
Muscle glycogen concentrations and response to diet and exercise regimes in Warmblood horses with type 2 Polysaccharide Storage Myopathy. PLoS One 13:e0203467, 2018. Pubmed reference: 30183782. DOI: 10.1371/journal.pone.0203467.
2017 Lewis, S.S., Nicholson, A.M., Williams, Z.J., Valberg, S.J. :
Clinical characteristics and muscle glycogen concentrations in warmblood horses with polysaccharide storage myopathy. Am J Vet Res 78:1305-1312, 2017. Pubmed reference: 29076373. DOI: 10.2460/ajvr.78.11.1305.
Valberg, S.J., Nicholson, A.M., Lewis, S.S., Reardon, R.A., Finno, C.J. :
Clinical and histopathological features of myofibrillar myopathy in Warmblood horses. Equine Vet J 49:739-745, 2017. Pubmed reference: 28543538. DOI: 10.1111/evj.12702.

Edit History


  • Created by Imke Tammen2 on 20 Apr 2021
  • Changed by Imke Tammen2 on 20 Apr 2021
  • Changed by Imke Tammen2 on 17 Jun 2021