glycogen storage disease III

Glycogen Storage Disease Type III (GSDIII): An Overview

Glycogen storage disease type III, also known as GSDIII or Cori disease, is a rare inherited disorder caused by the buildup of abnormal glycogen in the body's cells. This condition impairs the function of certain organs and tissues, particularly the liver and muscles.

Key Features:

• Inherited Disorder: GSDIII is an autosomal recessive disorder, meaning that both parents must be carriers to pass on the mutated gene.
• Abnormal Glycogen Accumulation: The disease is characterized by the accumulation of structurally abnormal glycogen in cells, which impairs their function.
• Liver and Muscle Involvement: GSDIII primarily affects the liver and muscles, leading to various symptoms and complications.

Symptoms and Complications:

• Symptoms often appear in infancy or childhood, with the liver being enlarged (hepatomegaly) and causing a swollen abdomen.
• The accumulated glycogen impairs the function of certain organs and tissues, especially the liver and muscles.
• Variable clinical severity affects primarily the liver, heart, and skeletal muscle.

Subtypes:

• GSDIIIa is the most common subtype, present in about 85% of affected individuals, manifesting with liver and muscle involvement.
• GSDIIIb, with liver involvement only, comprises about 15% of all affected individuals.

Incidence:

• The highest incidence of glycogen storage disease type III is in the Faroe Islands, where it occurs in 1 out of every 3,600 births, likely due to a founder effect.
• GSDIII affects approximately 1 in 100,000 live births worldwide.

References:

• [1] Description. Glycogen storage disease type III (also known as GSDIII or Cori disease) is an inherited disorder caused by the buildup of a complex sugar called glycogen in the body's cells.
• [2] GSD III is AR. In regards to genetics glycogen storage disease type III is inherited in an autosomal recessive pattern.
• [3] Oct 12, 2017 — In these patients, the breakdown of glycogen (glycogenolysis) is defective.
• [5] by CP Sentner · 2016 · Cited by 169 — Glycogen storage disease type III (GSDIII) is a rare disorder of glycogenolysis due to deficiency of the debranching enzyme.
• [15] Clinical characteristics: Glycogen storage disease type III (GSD III) is characterized by variable liver, cardiac muscle, and skeletal muscle involvement.

Glycogen storage disease type III (GSD III), also known as Cori disease, is a rare inherited disorder that affects the body's ability to break down glycogen, a complex carbohydrate stored in the liver and muscles. The signs and symptoms of GSD III can vary depending on the subtype and individual affected.

Common Signs and Symptoms:

• Hepatomegaly (enlarged liver): A swollen abdomen due to an enlarged liver is a common sign of GSD III.
• Growth delay: Growth retardation during childhood is another characteristic feature of this disease.
• Low blood sugar (hypoglycemia): Individuals with GSD III often experience episodes of low blood sugar, which can cause fatigue, constant hunger, and crankiness.
• Elevated fat levels in blood: High levels of fats in the blood are also a common symptom of GSD III.

Other Possible Signs and Symptoms:

• Muscle weakness: Muscle involvement is another characteristic feature of GSD III, leading to muscle weakness and wasting.
• Cardiac involvement: Some individuals with GSD III may experience cardiac symptoms, such as arrhythmias or heart failure.
• Thin upper lip vermilion: A thin upper lip vermilion and other facial abnormalities have been reported in some cases.

Important Notes:

• The signs and symptoms of GSD III can vary depending on the subtype and individual affected.
• Early diagnosis and treatment are essential to manage the disease and prevent complications.
• Currently, there is no cure for GSD III, but various treatments aim to alleviate symptoms and improve quality of life.

References:

[8] Type III - Cori's Disease · Swollen abdomen due to an enlarged liver · Growth delay during childhood · Low blood sugar · Elevated fat levels in blood · Possible ...

[9] A buildup of abnormal glycogen damages organs and tissues throughout the body, particularly the liver and muscles, leading to the signs and symptoms of GSDIII.

[10] Glycogen storage disease type III (GSD III) is characterized by variable liver, cardiac muscle, and skeletal muscle involvement. GSD IIIa is the most common subtype, present in about 85% of affected individuals; it manifests with liver and muscle involvement. ... It is not known whether cardiac signs and symptoms can be avoided with optimal ...

[14] Patients with glycogen storage disease type III also have elevated creatine kinase levels. Glycogen storage disorder type I is associated with elevated levels of lactic acid and acidosis. ... Currently, there is no cure for any GSD, and most treatments attempt to alleviate signs/symptoms.

Glycogen storage disease type III (GSDIII) can be diagnosed through various tests that assess the function and structure of the liver, muscles, and other organs affected by the condition.

• Liver biopsy: A liver biopsy is a key diagnostic test for GSDIII. It involves taking a small sample of liver tissue, which is then examined under a microscope to look for abnormal glycogen accumulation ([2], [6]). This test can also measure the activity of the enzymes hepatic phosphorylase in the liver and muscle ([6]).
• Blood tests: Blood tests can be used to measure the levels of certain enzymes involved in glycogen metabolism, such as debranching enzyme activity ([10], [12]). These tests can help confirm a diagnosis of GSDIII.
• Genetic testing: Genetic testing is also available for GSDIII. This involves analyzing DNA samples from an individual or their family members to identify mutations in the AGL gene that cause the condition ([8], [15]).
• Muscle biopsy: In some cases, a muscle biopsy may be performed to assess muscle function and look for signs of glycogen accumulation ([7]).

It's worth noting that diagnosis can take time, as GSDIII is a rare condition. Healthcare providers may need to rule out other conditions before making a definitive diagnosis. A comprehensive diagnostic evaluation should involve a team of interprofessional healthcare providers working together to ensure accurate diagnosis and effective management ([11]).

Current Treatment Options for Glycogen Storage Disease Type III

Unfortunately, there are no effective treatments available specifically for Glycogen Storage Disease type III (GSD III). However, various management strategies can help alleviate symptoms and improve quality of life.

• No specific drugs: According to search result [2], there are no reports in the literature of drugs that are effective in treating GSD types III, IV, V, and VII.
• Creatine supplement: Some patients with GSD type V may benefit from creatine supplements (search result [2]).
• General management strategies: Treatment for manifestations such as muscle weakness, fatigue, and liver dysfunction can be managed through general measures like:
  • High carbohydrate intake
  • Steroid-based drugs
  • Growth hormone replacement therapy
  • Medications that can cause rhabdomyolysis (use with caution)
  • Hormonal contraceptives
  • Statins for control of hyperlipidemia
  • Beta blockers

Please note that these management strategies are not specific to GSD III and may be used in conjunction with other treatments.

References:

• [2] No effective treatment is available for GSD types III, IV, V, and VII.
• [11] High carbohydrate intake, steroid-based drugs, growth hormone replacement therapy, medications that can cause rhabdomyolysis. Use with caution: hormonal contraceptives, statins for control of hyperlipidemia, and beta blockers.

Note: The references provided are based on the search results within the context block.

Glycogen storage disease type III (GSD III) can be challenging to diagnose due to its variable clinical presentation and overlap with other conditions. However, a comprehensive differential diagnosis is essential for accurate identification.

Key Conditions to Consider:

• Glycogen Storage Disease Type I (GSD I): Also known as von Gierke disease, this condition presents with severe hypoglycemia, lactic acidosis, and hepatomegaly. While it primarily affects the liver, some cases may involve muscle weakness and fatigue.
• Glycogen Storage Disease Type VI (GSD VI): This condition is characterized by mild to moderate hypoglycemia, lactic acidosis, and hepatomegaly. It often presents with a more gradual onset than GSD I.
• Glycogen Storage Disease Type IX (GSD IX): Also known as Forbes disease, this condition shares similarities with GSD III in terms of its clinical presentation, including muscle weakness, fatigue, and hypoglycemia.
• Other Metabolic Disorders: Conditions like Pompe disease, McArdle disease, and Tarui disease can also present with similar symptoms, making differential diagnosis crucial.

Clinical Features to Consider:

• Hepatomegaly: Enlarged liver is a common feature in GSD III, but it's not exclusive to this condition.
• Muscle Weakness and Fatigue: These symptoms are often seen in GSD III, particularly in the more severe forms like GSD IIIa.
• Hypoglycemia: Low blood sugar levels can occur in GSD III, especially during fasting or exercise.
• Lactic Acidosis: Elevated lactic acid levels may be present in some cases of GSD III.

Diagnostic Approaches:

• Genetic Testing: Molecular analysis can confirm the presence of mutations in the AGL gene, which is responsible for glycogen debranching enzyme deficiency.
• Enzyme Assays: Measuring glycogen debranching enzyme activity in liver or muscle tissue can help diagnose GSD III.
• Imaging Studies: Ultrasound and CT scans may reveal hepatomegaly or other abnormalities.

Conclusion:

Differential diagnosis of glycogen storage disease type III requires a thorough understanding of the clinical presentation, genetic basis, and diagnostic approaches. A comprehensive evaluation, including genetic testing, enzyme assays, and imaging studies, is essential for accurate identification and management of this condition.