Definition of Von Gierke disease:

Von Gierke disease is a disorder of metabolism in which the body cannot break down glycogen for energy. Gycogen is stored in the liver and muscles and is normally broken down into glucose when you do not eat.

Von Gierke disease is also called Type I glycogen storage disease (GSD I).

Causes, incidence, and risk factors:

Von Gierke disease occurs when the body lacks the specific protein (enzyme) that releases glucose from glycogen. This causes abnormal amounts of glycogen to build up in various tissues, leading to low blood sugar.

Von Gierke disease is inherited, which means it is passed down through families. If both parents carry the defective gene related to this condition, each of their children has a 25% chance of developing the disease.

Symptoms:

• Severe low blood sugar (hypoglycemia)
• Puffy cheeks, thin chest and limbs, and swollen belly
• Constant hunger and need for frequent feedings
• Stunted growth or growth failure
• Delayed or underdeveloped puberty
• Enlarged liver
• Fatigue
• Irritability
• Gout (a painful inflammation of joints)
• Easy bruising and nosebleeds

Signs and tests:

The health care provider will perform a physical exam. There may be signs of a swollen liver and liver tumors. Children with this condition are usually diagnosed before age 1.

Tests that may be done include:

• Biopsy of liver or kidney
• Blood sugar test
• Genetic testing
• Lactic acid blood test
• Triglyceride level
• Uric acid blood test

Testing reveals low blood sugar and high levels of lipids and uric acid.

Treatment:

The goal of treatment is to avoid low blood sugar. Frequent feedings are needed during the day, especially with foods that contain carbohydrates (starches). Older children and adults may take cornstarch by mouth.

Overnight, a feeding tube is placed through the nose into the stomach to provide a supply of sugars or uncooked cornstarch. The tube can be put in at bedtime and taken out each morning.

A medication called allopurinol, which can lower blood uric acid and decrease the risk for gout, may also be prescribed.

Persons with von Gierke disease cannot properly break down fruit or milk sugar, so such products are best avoided.

Support Groups:

Association for Glycogen Storage Disease -- www.agsdus.org

Expectations (prognosis):

Since development of the treatments listed above, growth, puberty, and quality of life have markedly improved for those with von Gierke disease. Those who are identified and carefully treated at a young age can live into adulthood.

Early treatment also decreases the rate of severe problems such as liver tumors, kidney failure, gout and life-threatening low blood sugar.

Complications:

• Seizures, lethargy, confusion due to low blood sugar
• Gout
• Kidney failure
• Liver tumors
• Short adult stature
• Underdeveloped secondary sexual characteristics
• Osteoporosis
• Ulcers of the mouth or bowel
• Frequent infection

Calling your health care provider:

Call your health care provider if there is a family history of glycogen storage disease or early infant death due to low blood sugar.

Prevention:

There is no simple way to prevent glycogen storage disease.

Couples who wish to have a baby may seek genetic counseling and testing to determine their risk for passing on von Gierke disease.