Polysaccharide Storage Myopathy – PSSM1
Code: P678
Short description
Polysaccharide Storage Myopathy 1 (PSSM1 or PSSM Type 1) is a muscle disorder characterized by the abnormal buildup of glycogen (complex sugars) in skeletal muscle cells.
General information
Polysaccharide Storage Myopathy 1 (PSSM1 or PSSM Type 1) is a muscle disorder characterized by the abnormal buildup of glycogen (complex sugars) in skeletal muscle cells. This excess glycogen leads to the breakdown of muscle fibers, resulting in a range of symptoms, from muscle atrophy and progressive weakness to muscle soreness and gait abnormalities. PSSM Type 1 is caused by an incomplete autosomal dominant mutation in the glycogen synthase 1 (GYS1) gene.
Specifications
| Breeds | All Breeds |
|---|---|
| Gene | GYS1 |
| Chromosome | 10 |
| Mutation | c.926G>A |
| Organ | Muscles |
| Specimen | Hair, Blood EDTA, Blood Heparin, Semen, Tissue |
| Mode of Inheritance | Autosomal Incomplete Dominant |
| Also known as | PSSM1 |
Clinical features
The severity of clinical signs in PSSM can vary, ranging from mild muscle soreness and weakness to acute exertional rhabdomyolysis (muscle fiber breakdown) and severe muscle atrophy, which can make a horse reluctant to move. The most common clinical signs include sweating, muscle stiffness, and reluctance to move, often accompanied by increased serum creatine kinase levels. These signs typically appear when horses begin training, with episodes often starting after light exercise, usually within 30 minutes of walking.
Additional information
The PSSM1 variant does not account for all cases of abnormal glycogen buildup in muscles. Other genetic factors may contribute to this condition, but so far, no genetic variants for other types of PSSM (such as PSSM Type 2) have been identified or validated.
References
Pubmed ID: 18358695
Year published: 2008
Omia ID: 1158
Omia variant ID:
Turnaround information
- 20 working days