Pediatric glycogen storage disease (GSD)

What is pediatric glycogen storage disease (GSD)?

When a child has glycogen storage disease (GSD), it means they have a genetic disorder that changes the way their body uses and stores glycogen. 

Normally, glycogen is stored in the liver, where enzymes can break it down into glucose when the body needs more energy. When glycogen is not stored or used properly, or when the enzyme needed to break it down into glucose is missing, the glycogen builds up in the child’s tissues and can cause problems in the liver, muscles and organs. 

What are the different types of pediatric glycogen storage disease (GSD)?

There are eight types of glycogen storage disease, depending on the specific enzyme that is affected or missing.

The three most common types of the disease are:

1. Type I (Von Gierke disease) - this is the most common type of glycogen storage disease. In type I, the enzyme in the liver that is needed to turn glycogen into glucose is missing.
2. Type III (Cori disease or Forbes disease) - type III occurs when a child doesn’t have enough of the debranching enzyme, which helps break down glycogen.
3. Type IV (Andersen disease) - type IV causes abnormal formation of glycogen which triggers the body’s immune system to attack the liver and other organs. 

Other types include:

• Type II (alpha glucosidase deficiency - GAA, acid maltase deficiency or Pompe disease)
• Type V (McArdle disease)
• Type VI (Hers disease)
• Type VII (Tarui disease)

What are the signs and symptoms of pediatric glycogen storage disease (GSD)?

The symptoms of glycogen storage disease are similar for the most common types of the disease.

Symptoms include:

• Acidosis (high acid levels in the blood)
• Bruising easily
• Enlarged liver
• Hyperlipidemia (high blood cholesterol levels)
• Hypoglycemia (low blood sugar)
• Hypotonia (low muscle tone)
• Intolerance to hot weather
• Muscle cramps
• Slow growth
• Swollen abdomen