Sphynx and Devon Rex Congenital Myasthenic Syndrome (CMS)

Quick Summary

Congenital myasthenic syndrome causes a congenital muscle weakness in Devon Rex and Sphynx cats.

Phenotype: Congenital myasthenic syndrome (CMS) causes a congenital muscle weakness in Devon Rex and Sphynx breed cats. Moderate to severely affected cats show evidence of generalized muscle weakness, particularly following exertion, stress, or excitement. Affected cats frequently adopt a characteristic “dog-begging” or “chipmunk” position, usually with their front legs resting on a convenient object. Signs of the disease can be observed as early as of 3 weeks of age and progress slowly but occasionally do become static.

Mode of Inheritance: Autosomal recessive

Alleles: N = Normal/Unaffected, CMS = Congenital myasthenic syndrome

Breeds appropriate for testing: Devon Rex, Sphynx

Explanation of Results:

  • Cats with N/N genotype will not have this congenital myasthenic syndrome. They cannot transmit this CMS variant to their offspring.
  • Cats with N/CMS genotype will not have this congenital myasthenic syndrome, but are carriers. They will transmit this CMS variant to 50% of their offspring. Matings between two carriers are predicted to produce 25% congenital myasthenic syndrome-affected kittens.
  • Cats with CMS/CMS genotype will have congenital myasthenic syndrome, a progressive condition that can be fatal.
Price

$40 one test per animal

Additional Details

A mutation that causes a congenital muscle weakness in Devon Rex and Sphynx breed cats, initially reported as “Spasticity”, has been identified in the gene COLQ. The mutation results in a congenital myasthenic syndrome (CMS) similar to CMS in humans. The disease is inherited in an autosomal recessive fashion thus two copies of the mutation are necessary to observe the disease and both males and females are equally affected. Cats with a single copy are unaffected but are carriers.

Moderate to severely affected cats show evidence of generalized muscle weakness, particularly following exertion, stress, or excitement. Affected cats frequently adopt a characteristic “dog-begging” or “chipmunk” position, usually with their front legs resting on a convenient object. Cats with CMS generally succumb to the disease by asphyxiation due to choking on food or aspiration pneumonia by two years of age. Signs of the disease can be observed as early as of 3 weeks of age and progress slowly but occasionally do become static.

The disease was first described in the UK in 1989 with detailed presentations from Australia in 1993. Affected cats have been identified in the USA and more recently across Europe. Breeding two carrier cats is predicted to produce 25% affected offspring.

The mutation causing Sphynx and Devon Rex Congenital Myasthenic Syndrome was discovered by a world-wide research team of geneticists and neurologists from the University of Missouri, the University of California, Davis, the University of California, San Diego, the University of Sydney, and the University of Milan.

 

Acknowledgements

We appreciate the assistance of Nicholas Gustafson, the strong and long-standing dedication of cat breeders, Sybil Drummond and Pam Dowlings, Paolo Valiati, and the Italian Feline Biobank-Vetogene.

Research Funding

Funding was provided by the National Center for Research Resources R24 RR016094, the Winn Feline Foundation (W10 -014 , W11-041, MT13-010), the Phyllis and George Miller Trust (MT08-015), the University of California, Davis, Center for Companion Animal Health (2008-36-F, 2008-06-F) and the Cat Health Network (D12FE-510).

Turnaround Time
2-6 business days
Type of Sample

Species

Cat

Type of Test

Results Reported As
Test Result Sphynx and Devon Rex CMS status
N/N No copies of the CMS mutation. Cat is normal.
N/CMS

1 Copy of the CMS mutation. Cat is normal but is a carrier.

CMS/CMS

2 copies of the CMS mutation. Cat is or will be affected.

References

Lievesley, P., & Gruffydd-Jones, T. (1989). Episodic collapse and weakness in cats. Veterinary Annual, 29, 261-269.

Robinson, R. (1992). 'Spasticity' in the Devon rex cat. Veterinary Record, 130(14), 302.

Malik, R., Mepstead, K., Yang, F., & Harper, C. (1993). Devon rex cats. Journal of Small Animal Practice, 34, 539-546.

Shelton, G.D., Sturges, B., Lyons, L., Williams, D.C., Aleman, M., Jiang, Y., & Mizisin, A. (2007). Myopathy with tubulin-reactive inclusions in two cats. Acta Neuropathologica, 114(5), 537-542. doi: 10.1007/s00401-007-0217-6

Martin, P.T., Shelton, G.D., Dickinson, P.J., Sturges, B.K., Xu, R., LeCouteur, R.A., Guo, L.T., Grahn, R.A., Lo, H.P., & North, K.N. (2008). Muscular dystrophy associated with alpha-dystroglycan deficiency in Sphynx and Devon Rex cats. Neuromuscular disorders : NMD, 18(12), 942-952. doi: 10.1016/j.nmd.2008.08.002

Gandolfi, B., Grahn, R.A., Creighton, E.K., Williams, D.C., Dickinson, P.J., Sturges, B.K., Guo, L.T., Shelton, G.D., Leegwater, P.A.J., Longeri, M., Malik, R., & Lyons, L.A. (2015). COLQ variant associated with Devon Rex and Sphynx feline hereditary myopathy. Animal Genetics, 46(6), 711-715. doi: 10.1111/age.12350