equine genetic test data sheet
Equine hyperkalemic periodic paralysis
Test
code: GE001 - Detection of the gene responsible for
hyperkalemic periodic paralysis in horses, by polymerase chain reaction (PCR).
Hyperkalemic periodic paralysis (HYPP) is an autosomal dominant
inherited disease affecting the muscle tissue of horses. It is
usually caused by a point mutation in a protein that is part of
the sodium channel in muscle cells. Sodium channels are "pores"
in the muscle cell that regulate contraction of the muscle
fibers.
Muscles of affected horses can be overly excitable and contract
involuntarily. This occurs when potassium levels change in the
blood, for example when fasting is followed by consumption of a
high potassium feed such as alfalfa. High levels of potassium in
blood (hyperkalemia) cause the muscles to contract more readily
than normal, and thus affected horses will develop sporadic
episodes of muscle tremors or paralysis.
Most sporadic mutations in this gene are incompatible with
survival. However, one mutation, P1416L, that can be traced back
through descendants of the American Quarter Horse sire
Impressive (Tryon et al., 2009), produces a functional, yet
altered, sodium ion channel. Because of the lesser severity of
the deformation, horses with the P1416L mutation can survive but
still suffer from HYPP. This gene mutation is not a product of
inbreeding; the mutation inadvertently became widespread when
breeders sought to produce horses with heavy musculature.
Utilities:
-
Identify the genetic
cause of symptoms
-
Help confirm diagnosis
of genetic disease
-
Genetic assessment for
breeding control
References:
Tryon, R.C., Penedo, M.C., McCue, M.E., Valberg, S.J.,
Mickelson, J.R., Famula, T.R., Wagner, M.L., Jackson, M.,
Hamilton, M.J., Nooteboom, S. and Bannasch, D.L. (2009)
Evaluation of allele frequencies of inherited disease genes in
subgroups of American Quarter Horses.
J. Am. Vet. Med. Assoc.
234:120-125.
Specimen requirements:
Buccal swab, or 0.1 ml EDTA whole blood.
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.
If there
will be a delay in shipping, or during very warm weather,
refrigerate specimens until shipped and ship with a cold pack.
See shipping instructions
for more information.
Turnaround time:
3 business days
Methodology:
Qualitative
real time PCR
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