Phenotypes associated with the disease Glycogen storage disease due to muscle and heart glycogen synthase deficiency (ORPHA:137625):
- Exertional dyspnea (HP:0002875): Perceived difficulty to breathe that occurs with exercise or exertion and improves with rest. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:137625)
- Myalgia (HP:0003326): Pain in muscle. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:137625)
- Syncope (HP:0001279): A transient loss of consciousness (i.e., characterized by a rapid onset, a short duration, and a spontaneous and complete recovery) due to cerebral hypoperfusion. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:137625)
- Ragged-red muscle fibers (HP:0003200): An abnormal appearance of muscle fibers observed on muscle biopsy. Ragged red fibers can be visualized with Gomori trichrome staining as irregular and intensely red subsarcolemmal zones, whereas the normal myofibrils are green. The margins of affect fibers appear red and ragged. The ragged-red is due to the accumulation of abnormal mitochondria below the plasma membrane of the muscle fiber, leading to the appearance of a red rim and speckled sarcoplasm. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:137625)
- Exercise intolerance (HP:0003546): A functional motor deficit where individuals whose responses to the challenges of exercise fail to achieve levels considered normal for their age and gender. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:137625)
- Skeletal myopathy (HP:0003756). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:137625)
- Decreased muscle glycogen content (HP:0012270): A decreased amount of glycogen in muscle tissue. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:137625)
- Seizure (HP:0001250): A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:137625)
- Sudden cardiac death (HP:0001645): The heart suddenly and unexpectedly stops beating resulting in death within a short time period (generally within 1 h of symptom onset). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:137625)
- Left ventricular hypertrophy (HP:0001712): Enlargement or increased size of the heart left ventricle. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:137625)
- Difficulty climbing stairs (HP:0003551): Reduced ability to climb stairs. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:137625)