Glycogen Storage Diseases

Some of these diseases cause few symptoms. Others are fatal. The specific symptoms, age at which symptoms start, and their severity vary considerably between these diseases. For types II, V, and VII, the main symptom is usually weakness (myopathy). For types I, III, and VI, symptoms are low levels of sugar in the blood (hypoglycemia Hypoglycemia Hypoglycemia is abnormally low levels of sugar (glucose) in the blood. Hypoglycemia is most often caused by medications taken to control diabetes. Much less common causes of hypoglycemia include... read more ) and protrusion of the abdomen (because excess or abnormal glycogen may enlarge the liver). Low levels of sugar in the blood cause sweating, confusion, and sometimes seizures and coma. Other consequences for children may include stunted growth, frequent infections, and sores in the mouth and intestines.

Glycogen storage diseases tend to cause uric acid (a waste product) to accumulate in the joints, which can cause gout Gout Gout is a disorder in which deposits of uric acid crystals accumulate in the joints because of high blood levels of uric acid (hyperuricemia). The accumulations of crystals cause flares (attacks)... read more , and in the kidneys, which can cause kidney stones Stones in the Urinary Tract Stones (calculi) are hard masses that form in the urinary tract and may cause pain, bleeding, or an infection or block of the flow of urine. Tiny stones may cause no symptoms, but larger stones... read more . In type I glycogen storage disease, kidney failure is common at age 11 to 20 years or later.

Glycogen storage disease is diagnosed by examining a piece of muscle or liver tissue under a microscope (biopsy) and by doing magnetic resonance imaging Magnetic Resonance Imaging (MRI) Magnetic resonance imaging (MRI) is a type of medical imaging that uses a strong magnetic field and very high frequency radio waves to produce highly detailed images. During an MRI, a computer... read more (MRI) to detect glycogen in the tissues. Doctors confirm the diagnosis by analyzing the DNA. Glycogen storage disease type II (Pompe disease) is now part of the screening test for newborns Newborn Screening Tests Screening tests are done to detect health conditions that are not yet causing symptoms. Many serious disorders that are not apparent at birth can be detected by various screening tests. Early... read more in many states. Other tests, such as liver, skin, muscle, and blood tests, are done to determine the specific type of glycogen storage disease. Genetic testing Genetic Screening Before Pregnancy Genetic screening is used to determine whether a couple is at increased risk of having a baby with a hereditary genetic disorder. Hereditary genetic disorders are disorders of chromosomes or... read more to determine whether a couple is at increased risk of having a baby with a hereditary genetic disorder is also available. See also diagnosis of hereditary disorders of metabolism Diagnosis Hereditary metabolic disorders are inherited genetic conditions that cause metabolism problems. Heredity is the passing of genes from one generation to the next. Children inherit their parents'... read more .

Treatment depends on the type of glycogen storage disease.

For most types, eating many small carbohydrate-rich meals every day helps prevent blood sugar levels from dropping.

For people who have glycogen storage diseases that cause low blood sugar levels, levels are maintained by giving uncooked cornstarch every 4 to 6 hours around the clock, including overnight.

For others, it is sometimes necessary to give carbohydrate solutions through a stomach tube all night to prevent low blood sugar levels from occurring at night.

People who have a glycogen storage disease that affects the muscles should avoid excessive exercise.

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