Devon Rex myopathy in Cats (Felis) | Vetlexicon
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Devon Rex myopathy

ISSN 2398-2950


Introduction

  • Cause:  hereditary condition with a suspected highly penetrant autosomal recessive mode of inheritance.
  • Signs:  generalized muscle weakness (especially dorsal cervical and thoracic limb girdle muscle groups), head bobbing, passive ventro-flexion of the head and neck, dorsal protrusion of the scapulae, fatigability, slightly high stepping gait, megaesophagus, low head carriage, "dog-begging" posture.
  • Diagnosis:  muscle biopsy and immunohistochemical staining for alpha-dystroglycan protein.
  • Treatment:  no specific treatment. Keep indoors. Feeding from a platform can be helpful. Small feeds are better than large meals.
  • Prognosis:  guarded, although mildly affected individuals can have a long happy life; severely affected individuals have poor quality of life and often die after choking on food.

Presenting signs

  • Ventro-flexion of the neck with the chin tucked into the sternum.
  • Generalized muscle weakness.
  • Head bobbing or head nodding.
  • High stepping gait.
  • Dorsal protrusion of the scapulae  Devon Rex: myopathy .
  • Fatigability.
  • Megaesophagus  Megaesophagus.
  • Low head carriage.
  • "Dog-begging" or "chipmunk" or "Meeercat" posture or periscoping.

Acute presentation

  • Can develop upper airway obstruction due to accumulation of ingesta in the vicinity of the larynx.

Age predisposition

  • Congenital, clinical signs first appear between 3 and 23 weeks of age.

Breed/Species predisposition

Special risks

  • Anesthetic risks relating to neuromuscular weakness (risk of laryngeal, pharyngeal and intercostal muscle weakness). Normally they can be safely anesthetized for muscle biopsy under general anesthesia.

Pathogenesis

Etiology

  • Hereditary condition with a suspected autosomal recessive mode of inheritance.
  • A genome-wide association study and whole-genome sequencing suggested a causal variant for this entity was a c.1190G>A variant causing a cysteine to tyrosine substitution (p.Cys39Tyr) within the C-terminal domain of collagen-like tail subunit (single strand of homotrimer) of asymmetric acetylcholinesterase (COLQ).
  • Alpha-dystroglycan expression, which is associated with COLQ anchorage at the motor endplate, has been shown to be deficient in affected cats.

Pathophysiology

  • Results from a deficiency in alpha-dystroglycan protein expression which is an extracellular membrane-associated protein that binds to a variety of extracellular matrix proteins.

Timecourse

  • Congenital, progressive onset between 3 and 23 weeks of age.
  • Usually slowly progressive.
  • Some individuals are much worse affected than others.

Diagnosis

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Treatment

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Prevention

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Abitbol M, Hitte C, Bossé P et al (2015) A COLQ missense mutation in Sphynx and Devon Rex cats with congenital myasthenic syndrome. PLoS ONE 10 (9), e0137019 PubMed.
  • Gandolfi B, Grahn R A, Creighton E K et al (2015) COLQ variant associated with Devon Rex and Sphynx feline hereditary myopathy. Anim Genet 46 (6), 711-715 PubMed.
  • Martin P T, Shelton G D, Dickinson P J et al (2008) Muscular dystrophy associated with alpha-dystroglycan deficiency in Sphynx and Devon Rex cats. Neuromuscul Disord 18 (12), 942-952 PubMed.
  • Shelton G D, Sturges B K, Lyons L A et al (2007) Myopathy with tubulin-reactive inclusions in two cats. Acta Neuropathol 114 (5), 537-42 PubMed.
  • Malik R, Mepstead K, Yang F et al (1993) Hereditary myopathy of Devon Rex cats. J Small Anim Pract 34 (11), 539-546 VetMedResource.
  • Lievesley P, Gruffyd-Jones T (1989) Episodic weakness and collapse in cats. Vet Annu 29, 261-269 VetMedResource.