Polysaccharide storage myopathy (PSSM) is characterized by the abnormal accumulation of the normal form of sugar stored in muscle (glycogen) as well as an abnormal form of sugar (polysaccharide) in muscle tissue. Thousands of horses have been identified with tying-up associated with polysaccharide accumulation in muscles. Horses with PSSM have signs typically associated with tying-up. Most commonly these signs are muscle stiffness, sweating and reluctance to move. The signs are most often seen in horses when they are put into initial training or after a lay-up period when they receive little active turn-out. Episodes usually begin after very light exercise such as 10-20 minutes of walking and trotting. Horses with PSSM can exhibit symptoms without exercise. Most horses with PSSM have a history of numerous episodes of muscle stiffness at the commencement of training; however, mildly affected horses may have only one or two episodes/year. PSSM is a muscle disease in horses with Quarter Horse bloodlines such as Quarter Horses, American Paint Horses and Appaloosas. PSSM also occurs in many other breeds including Drafts, Draft crossbreeds and warmbloods.
The DNA test is performed out of EDTA blood or or 20-30 hair roots from mane or tail. Test kits can be ordered free of charge. (order-form). If hair is sent in, possibly the genetic material is not sufficient to run the test. In this case it would be best to send in an EDTA blood sample.
Please send in your sample together with the lab order genetic. Results will be transmitted optionally via post, fax or email. After completion of the test you will receive a separate invoice. Payment can be made via credit card or bank transfer. Breeding club discounts apply if a copy of the membership card is sent together with the respective samples. Due to administrative reasons the invoiced price can not be altered subsequently.