Phenotype: Malignant hyperthermia (MH) is an inherited disease in which affected horses can be triggered by halogenated anesthetics, succinylcholine, stress, or excitement, which can induce a hyper-metabolic state characterized by symptoms including muscle contracture, elevated temperature, and an irregular heart rhythm.
Mode of Inheritance: Autosomal dominant
Alleles: N = Normal/Unaffected, MH = Malignant hyperthermia
Breeds appropriate for testing: Quarter Horse and related breeds
Explanation of Results:
- Horses with N/N genotype will not have malignant hyperthermia and cannot transmit this malignant hyperthermia variant to their offspring.
- Horses with N/MH genotype will be affected by malignant hyperthermia. They can transmit this malignant hyperthermia variant to their offspring. Matings with N/N genotype will result in a 50% chance of producing a malignant hyperthermia-affected foal.
- Horses with MH/MH genotype will have malignant hyperthermia.