What Is the Life Expectancy of Someone With Glycogen Storage Disease?

Glycogen storage disease (GSD) is a relatively uncommon metabolic disorder. The body loses its ability to efficiently store or destroy glycogen. Depending on the specific type, GSD can harm the muscles, liver, and other organs.

Glucose is needed as a steady source of fuel for cells to function. The food is broken down into different nutrient components, including glucose. The liver and muscle cells store the additional glucose produced by the body as glycogen. When the body requires more energy, enzymes carry out glycogen metabolism or glycogenolysis, which transforms stored glycogen into glucose.

Children with GSD lack one of the numerous enzymes required to break down glycogen. Glycogen builds up in the liver and causes symptoms. This can cause low blood glucose levels or hypoglycemia during periods of fasting (between meals or at night).

GSD is hereditary; it is transmitted from parents to offspring. For most GSD subtypes, both parents are unaffected carriers. Each parent has one defective copy of the gene that causes GSD and one healthy copy of the gene. A child who receives defective copies of the gene from both parents will get GSD. Most cases of GSD gets identified during the first year of birth.

The body breaks down glycogen using numerous different enzymes. Types of glycogen storage disease (GSD) are determined by the deficient enzyme.

1. Type 0 (Lewis’ disease): Caused by glycogen synthase deficiency and affects the liver.
2. Type I (von Gierke’s disease): Caused by a defect in glucose-6-phosphatase.
3. Type IA: Affects the liver, kidneys, and intestines
4. Type IB: Affects the liver, kidneys, intestines, and blood cells.
5. Type II (Pompe’s disease): Caused by acid maltase deficiency affects muscles, heart, liver, nervous system, and blood vessels.
6. Type III (Forbes-Cori disease): Caused by debrancher enzyme deficiency and affects the liver, heart, skeletal muscles, and blood cells.
7. Type IV (Andersen’s disease): Caused by brancher enzyme deficiency and affects the liver, brain, heart, muscles, skin, and nervous system.
8. Type V (McArdle’s disease): Affects skeletal muscles.
9. Type VI (Hers’ disease): Caused by liver phosphorylase deficiency and affects the liver and blood cells.
10. Type VII (Tarui’s disease): Affects skeletal muscles and blood cells.
11. Type IX (Hers’ disease): Caused by liver glycogen phosphorylase kinase deficiency and affects the liver.
12. Type XI (Fanconi-Bickel syndrome): Affects the liver, kidneys, and intestines.

The signs and symptoms of children with glycogen storage disease (GSD) vary by kind. Typical symptoms of glycogen storage disease are

• Enlarger liver
• Low blood sugar
• Modest growth
• Muscle pain

Signs of specific types of glycogen storage diseases

Type I (von Gierke disease)

• Low blood sugar after a short period of fasting
• Slowed development and delayed puberty
• Increased oral infections and ulcers
• A large, fatty liver and enlarged kidneys
• Blood with high quantities of lactate, lipids, and uric acid
• Osteoporosis (weak bones with increased risk of fractures)

Type II (Pompe's disease)

• Enlarged liver and heart growth
• In extreme cases of GSD
  • Cardiac issues and muscle weakness emerge
  • Heart failure by the age of 18 months
• Milder types of type II might not result in heart issues

Type III (Forbes-Cori disease)

• Abdominal bloating brought on by an enlarged liver
• Juvenile growth retardation
• Reduced blood sugar
• Elevated fat levels in the blood
• Weak muscles

Type IV (Andersen's disease)

• Juvenile growth retardation
• Enlarged liver
• Progressive cirrhosis of the liver (which may lead to liver failure)
• May affect muscles and the heart

Type V (McArdle’s disease)

• Extreme exhaustion immediately following activity
• Cramps in the muscles during exercise
• Burgundy-colored urine after exercise

Types VI, IX (Hers’ disease)

• Liver enlargement occurs but diminishes with age
• Reduced blood sugar

Type I glycogen storage disease (GSD) has been linked to mutations in two genes. GSD type IA occurs due to mutations in the G6PC gene. It accounts for about 80 percent of type I GSD and caused glucose-6-phosphatase enzyme deficiency.

Mutations in the SLC37A4 gene result in glucose-6-phosphatase translocase enzyme deficiency. GSD type IB is responsible for about 20 percent of type I GSD. Both enzyme deficiencies cause an excessive buildup of glycogen and fat in the body's tissues.

The treatment options for glycogen storage disease (GSD) vary depending on the specific type of the disorder and the severity of the symptoms.

• Diet modification: A special diet that limits the intake of carbohydrates and provides sufficient protein and fat to meet the body's energy needs can treat some types of GSD. This can help prevent the accumulation of glycogen in the liver and other organs and improve the symptoms.
• Enzyme replacement therapy: Replaces the missing enzyme and helps the body to break down glycogen more effectively.
• Liver transplantation: Used for severe cases of GSD. This can improve the body's ability to break down glycogen and could be lifesaving in some cases.
• Medications: Help the body break down glycogen more effectively and prevent its accumulation in the liver and other organs. Glucagon stimulates the breakdown of glycogen in the liver, and insulin helps lower high blood sugar levels.
• Regular monitoring: Controls GSD by identifying and addressing any potential complications and may include regular blood tests, physical exams, and other diagnostic tests.

The specific treatment plan for GSD will depend on the individual needs and circumstances of the person with the disorder.