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Your GSD0 coordinator is
Abbie Maguire


The enzyme glycogen synthase is needed for the body to make glycogen. There are liver and muscle types of GSD0, both are inherited  in the autosomal recessoive pattern.

Liver type

A fault  in the GYS2 gene results in very low amounts of glycogen stored in the liver. A person between meals can develop very low blood sugar levels, known as hypoglycemia. Early in infancy children usually have no symptoms. The hypoglycemia typically develops once night feeding stops. Before breakfast children may have drowsiness, look pale, have vomiting, fatigue and sometimes convulsions. If a GP investigates a child lacking energy, hypoglycemia is often discovered through morning urine samples.

Muscle type

A fault  in the GYS1 gene results in very low amounts of glycogen stored in the skeletal muscles. This muscle type is extremely rare and little is known about it.

Other names

Glycogen synthase deficiency


Liver and muscle types

Inheritance Autosomal recessive

Less than 1 in 1,000,000

UK diagnosed Under 20  (UK diagnosed explained)
Liver type Muscle type

Before breakfast drowsiness, tiredness, looking pale, vomiting.

Exercise intolerance

Secondary symptoms

Quick to tire, muscle cramps

Muscle cramps, rhabdomyolysis


Regular snacks, cornstarch to reduce overnight hypoglycemia.

No proven treatment


Good with adherence to recommended feeding.

Good with avoidance of anaerobic activity

How can we help?


Diagnosis & Follow up

Incidence, Diagnosis, Treatment


Information & Support

Support, Coordinator, GSD and Me web site, Links


Activity & Exercise

Nothing available in this section yet.

Research & Development

Joining a trial

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