Type VII Glycogen Storage Disease Clinical Presentation

Updated: Aug 02, 2021
  • Author: Natapat Chaisidhivej, MD; Chief Editor: George T Griffing, MD  more...
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Severity varies based on an individual's enzyme activity level. Symptoms typically present in childhood, including exercise intolerance (premature fatigability), weakness and stiffness with exercise, and painful muscle cramps. Most symptoms resolve with resting. Sometimes, symptoms can be of late onset. [18, 19]

Exercise intolerance is noted in childhood much earlier and is more severe in Tarui disease than in McArdle disease. The second wind phenomenon is not seen in Tarui disease as it is in McArdle disease. Haller and Vissing concluded that the inability to properly metabolize blood glucose prevents the spontaneous second wind. [20]

Patients can present with myoglobinuria and rhabdomyolysis. Exantus et al report one case of acute renal failure secondary to rhabdomyolysis. [21]

Finsterer et al reported on one patient who was followed up for several years. [22, 23] Neurologic symptoms believed attributable to Tarui disease included complex partial seizures, diplopia, hyporeflexia, central facial palsy, and upper extremity weakness.



Physical Examination

Physical examination findings may be normal; therefore, clinical suspicion must be derived from patient history findings.

Muscle weakness after exercise, muscle contracture, and signs of hemolysis, including anemia and jaundice, may be detected. Hypotonia, seizure, blindness, catatacts, and cardiomyopathy can be found in the infantile form. [13, 14, 15]

Laboratory and procedural studies may be helpful to confirm the diagnosis. (See Workup for more detail.)