Categories: Muscle phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 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

Disease-related: 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: Arab (Horse) (VBO_0000905).
Breeds in which the phene has been documented. (If a likely causal variant has been documented for the phene, see the variant table breeds in which the variant has been reported).