GSD0 is incredibly rare and diagnosis may be difficult to achieve, but then there is help and guidance available.
Incidence
GSD0 is very rare, the muscle type being even more rare than the liver type. The recent availability of better genetic testing may show it to be less rare. The condition affects both males and females and cases have been seen around the world.
Finding a diagnosis
Children may become tired more quickly than their peers. There may be muscle cramps from accumulated lactic acid.
Liver type
Children may have a mild growth delay, but in general will develop normally, with normal appearance and liver size. A history of needing frequent meals or snacks, tiring quickly and hypoglycemia may suggest GSD0. Detailed blood and urine tests may show patterns that are unique to GSD0 and a liver biopsy will show very little glycogen.
Genetic testing
DNA testing is now available, the condition being caused by a change in the glycogen synthase-2 (GYS2) gene for the liver type and the glycogen synthase-1 (GYS1) gene for the muscle type.
Both the liver and muscle types are inherited in an autosomal recessive fashion.