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avian & livestock genetic test data sheet
Swine Malignant Hyperthermia (MH) detection by PCR
+ RFLP
Test code
GS002
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Identification of Malignant Hyperthermia (RyR1 R615C mutation)
in pigs, by PCR+RFLP
Malignant hyperthermia (MH) in swine is caused by calcium dysregulation
in muscle that can lead to sudden death and/or PSE (pale, soft,
and exudative) meat. This disease is a rare life-threatening
disease that is usually triggered by exposure to certain drugs
used for general anesthesia, such as the volatile anesthetic
agents and succinylcholine (a neuromuscular blocking agent). In
susceptible individuals, these drugs can induce a drastic and
uncontrolled increase in oxidative metabolism in skeletal
muscle, which surpasses the body's capacity to supply enough
oxygen, remove carbon dioxide, and regulate body temperature.
Susceptible individuals eventually develop circulatory collapse
and death if they are not immediately treated.
Recently, a mutation in ryanodine receptor 1 (RyR1 R615C mutation)
has been found to be associated with MH. Ryanodine receptor 1,
also known as skeletal muscle calcium release channel, is a
calcium channel that mediates the release of Ca2+
from the sarcoplasmic reticulum into the cytoplasm and thereby
plays a key role in triggering muscle contraction following
depolarization of T-tubules. The receptor can also mediate the
release of Ca2+ from intracellular stores in neurons,
and may thereby promote prolonged Ca2+ signaling in
the brain. The normal functioning of this receptor is required
for normal embryonic development of muscle fibers and skeletal
muscle, normal heart morphogenesis, skin development, and
ossification during embryogenesis.
In the last several decades, extensive inbreeding of pigs to achieve
better growth rate and meat quality has resulted in pigs with
this mutation. This abnormality
enhances the opening of Ca2+ channels and inhibits
their closing, due to an altered low-affinity Ca2+
binding site in the channel pore.
In pigs carrying this mutation, stress or sudden changes in their
environment may induce death. If these animals experience acute
stress just prior to slaughter, then large segments of the
carcasses result in pale, soft, exudative (PSE) pork (Rempel,
W.E. et al., 1995). The condition is sometimes referred to as
porcine stress syndrome (PSS) and is a serious economic problem
in the swine industry. Genetic screening of breeders is
important to help remove this mutation from herds.
Utilities:
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Identify and differentiate this mutation in swine
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Help remove this mutation from herds
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Enable breeding of pigs with specific genotypic
characteristics
References:
Rempel, W.E., Lu, M.Y., Mickelson, J.R. and Louis, C.F. (1995)
The effect of skeletal muscle ryanodine receptor genotype on pig
performance and carcass quality traits. Animal Sci. 6:249-257.
Specimen requirements: Buccal swab, or 0.2
ml whole blood in EDTA (purple top) or ACD (yellow top) tube, or
0.2 ml fresh, frozen or fixed tissue.
Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix to confirm specimen acceptability and shipping instructions.
For all specimen types, if there will be a delay in shipping, or
during very warm weather, refrigerate specimens until shipped
and ship with a cold pack unless more stringent shipping
requirements are specified. Frozen specimens should be shipped
so as to remain frozen in transit. See
shipping instructions for
more information.
Turnaround time: 3 business days
Methodology: PCR + restriction
fragment length polymorphism
Normal range:
Not detected
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