Dr. van Haeringen Laboratorium B.V.

P803 Polysaccharide Storage Myopathy 1 (Patent Lab)


PSSM Type 1 is a muscle disease in horses such as Quarter Horses, American Paint Horses and Appaloosas. Another form of polysaccharide storage myopathy also occurs in Draft, Draft crossbreeds, warmbloods. Many of the clinical signs in these breeds differ from those found in Quarter Horses and related breeds. The signs found in Draft, Draft crossbreeds, and warmbloods include muscle soreness, reluctance to engage the hind quarters muscle atrophy, and general weakness.

The signs are most often seen in horses when they are put into training. Episodes usually begin after very light exercise within half an hour of walking. During an episode, horses seem lazy followed by movements to stretch out as if to urinate. They are painful, stiff and sweat profusely.

Test specific information

This test is patented in certain countries. We offer our clients two options for this test because we are not allowed to perform the test in our laboratory. Firstly, the test can be ordered through a licensee of the patent owner. As a second option, the test can be forwarded to a partner laboratory in non-patented territory.

Between these two options, a price difference is in place which is caused by the royalties costs on the test. The tests performed by both labs are technical identical.


The genetic factor is continuously present, and will always be visible.

Turnaround time

The Turnaround Time (TAT) depends on various factors, such as the shipment time of your sample to the test location, the test method(s) and whether the tests are performed completely or partially by a Partner Lab or Patent owner.

The TAT of tests performed at our facilities is normally 10 working days after receipt of the sample at the testing laboratory (VHL, VHP or Certagen). For tests performed by a Partner Laboratory (so-called "partner lab test") or patent owner, the TAT is at least 20 working days after receipt of your sample. Because the shipment time to our Partner Labs or patent owner may vary due to factors we cannot influence, the mentioned 20 working days are therefore an estimate.

Sometimes it is necessary to re-run your sample. We call this a retest. In that case, the TAT will of course be extended.

Location of disease or trait

The disease is present in muscle. Depending on the effect, degeneration of muscle may take place. Alternatively, recovery following exercise may be deteriorated.

Breed dependence

This DNA test is available for the following breeds: American Paint Horse, Appaloosa, Draft Horses, New Forest, Quarter Horse, Tinker Horse, Warmblood. Additional information is available in the Frequently Asked Questions (FAQ).

Sample type

For this DNA test we accept the following materials: Hair, Semen, Blood EDTA, Blood Heparin. Please contact Dr. Van Haeringen Laboratorium if you wish to submit other material as listed.


An animal can be free and has in that situation two healthy alleles. When used in breeding this animal will not become ill due to the disease. It cannot spread the disease in the population.

An animal can be carrier and has in that situation one healthy and one disease allele. When used in breeding 50 percent of the offspring will receive the disease allele. Carriers will also become ill.

An animal can be affected and has in that situation two disease alleles. When used in breeding all offspring will also receive the disease allele. Affected will also become ill.


This genetic factor is inherited in an autosomal, dominant, mode. This means, that the individual can be free of the mutation (homozygote normal), affected (homozygous affected) or carrier (heterozygous affected). Both carriers and affected individuals will show symptoms of the mutation.

Severity of Disease


Code P803

Polysaccharide Storage Myopathy 1 (Patent Lab)

€ 127,05 (Incl. 21% VAT)
€ 105,00 (Excl. VAT)