About the Test
The PSSM1 DNA test verifies the presence of the affected allele at the GYS1 locus responsible for Polysaccharide Storage Myopathy Type 1 (PSSM1).
Sample Collection
Turnaround Time
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Standard Processing: Results in 5 working days after sample arrival at the laboratory. Clients organize and cover the costs of sending the samples.
Why Test?
This genetic test helps breeders identify horses carrying the PSSM allele. Informed breeding choices can prevent the birth of affected foals. While PSSM cannot be cured, muscle function can be managed with dietary changes and exercise routines.
The PSSM1 test is required by many studbooks and is highly recommended when considering the purchase of a horse. Testing for PSSM1 as part of the pre-purchase examination can ensure that you are making an informed decision, as the condition can impact the horse's performance and overall health.
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Results Description
The DNA test results will be one of the following:
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n/n: Negative for PSSM1. No affected allele present.
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n/P1: Positive heterozygous for PSSM1. One mutated allele present. The horse can pass the PSSM1 allele to 50% of its progeny.
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P1/P1: Positive homozygous for PSSM1. Two mutated alleles present. The horse will pass the PSSM1 allele to 100% of its offspring.
Additional Information
Polysaccharide Storage Myopathy (PSSM1) is a hereditary muscle disease that affects many breeds. The condition is caused by a mutation in the GYS1 gene, leading to an abnormal accumulation of glycogen in the muscles. This can cause symptoms such as muscle tremors, stiffness, reluctance to move, and excessive sweating. Management of PSSM1 includes dietary changes and regular exercise to help mitigate symptoms.
Check our FAQs for more information
FAQs
What breeds are affected by PSSM1?
PSSM1 affects many breeds, including Quarter Horses, Belgian Draft Horses, and Warmbloods. The prevalence of the mutation varies by breed, with some breeds having a higher incidence of the condition.
How is PSSM1 inherited?
PSSM1 is inherited in an autosomal dominant manner, meaning that horses with one (n/P1) or two (P1/P1) copies of the mutated gene can develop the disease. Horses with two copies generally show more severe symptoms.
How can PSSM1 be managed?
Management includes dietary modifications to reduce starch and sugar intake, and a consistent exercise regimen. These measures can help prevent the onset of symptoms or reduce their severity.
Visit our full FAQ page for more details.
