Malignant Hyperthermia

 

Gene: RYR1

Transmission: Autosomal dominant

For an autosomal dominant genetic disease, an animal must have at least one copy of the mutation in question to be at risk of developing the disease.  Animals with two copies of the mutation generally have more severe symptoms and an earlier onset of the disease than animals with just one copy of the mutation.  One or both of the parents of an animal with the mutation has one or two copies of the mutation.  Animals that have one or two copies of the mutation can pass the mutation on to future generations.

Mutation: Substitution, RYR1 gene; c.1643 T>C, p.(V548A)

Medical system: Metabolism

Breeds: Collie, Doberman Pinscher, English Springer Spaniel, German Shepherd, Labrador Retriever

Age of onset of symptoms: Triggered by stressful stimuli.

Malignant hyperthermia is a condition or disease that is triggered by various specific stimuli such as inhalation of anesthetic gas (halothane for example), muscle relaxants such as succinylcholine, ingestion of caffeine or intense physical exercise.  The affected animal then begins to experience violent muscle contractions and an increase in metabolic rate and heart rate which combine to increase the animal’s body temperature (hyperthermia).  Muscles become rigid and the animal can die, particularly if it is under anesthesia.

 

References:

OMIA link: [0621-9615]

Majchrakova Z, Hrckova Turnova E, Bielikova M, et al. (2023) The incidence of genetic disease alleles in Australian Shepherd dog breed in European countries. PLoS One 18:e0281215.  [pubmed/36848350]

Thrift E, Wimpole JA, Child G, et al. (2017) Exercise-induced hyperthermia syndrome (canine stress syndrome) in four related male English springer spaniels. Vet Med (Auckl) 8:59-68. [pubmed/30050857]

Brunson DB, Hogan KJ. (2004) Malignant hyperthermia: a syndrome not a disease.  Veterinary Clinics of North America: Small Animal Practice 34(6):1419-1433. [pubmed/15474681]

Roberts MC, Mickelson JR, Patterson EE, et al. (2001) Autosomal dominant canine malignant hyperthermia is caused by a mutation in the gene encoding the skeletal muscle calcium release channel (RYR1). Anesthesiology 95:715-25. [pubmed/11575546]