Von Gierke's disease A glycogen storage disease

What is glycogen and how is it mobilized?

Glycogen is a readily mobilised storage form of glucose, found mainly in the liver and skeletal muscle. It is present in the cytoplasm in the form of hydrated granules and is mobilized by phosphorylase (muscle and liver isoforms).

What is the structure of glycogen?

Glycogen is a branched polymer of glucose residues, with most glucose units linked by a (1→4) glycosidic bond. Branches are created by a (1→6) glycosidic bond at about every tenth residue.

What are the steps in glycogen degradation?

Glycogen degradation occurs in three steps: release of glucose-1-phosphate from glycogen by phosphorylase, remodelling of glycogen to permit further degradation by transferase and debranching enzyme, and conversion of glucose-1-phosphate to glucose-6-phosphate by phosphoglucomutase.

What is the relevance of glycogen?

Glycogen is a storage form of glucose and is used as a cell fuel. It can be broken down anaerobically or aerobically to yield pyruvate and is important for glucose homeostasis.

What is Von Gierke's disease?

Von Gierke's disease, also known as Glycogen Storage Disease Type I, is an autosomal recessive disorder caused by deficiency or dysfunction of enzymes involved in glycogen metabolism. It is characterized by hypoglycemia, hepatomegaly, nephromegaly, hyperlipidemia, growth retardation, and long-term renal and liver disease.

What is the relevance of glycogen?

Glycogen is a storage form of glucose and is used as a cell fuel. It can be broken down anaerobically or aerobically to yield pyruvate and is important for glucose homeostasis.

What enzymes are involved in glycogen synthesis?

Glycogen synthesis involves UDP-glucose as the activated glucose donor, glycogen synthase catalysing the synthesis of (1→4) bonds, and glycogenin as the primer. A branching enzyme is also needed.

What enzymes are involved in glycogen degradation?

Glycogen degradation involves phosphorylase (muscle and liver isoforms), transferase, debranching enzyme, and phosphoglucomutase.

What is Von Gierke's disease?

Von Gierke's disease, also known as Glycogen Storage Disease Type I, is an autosomal recessive disorder caused by deficiency or dysfunction of enzymes involved in glycogen metabolism. It is characterized by hypoglycemia, hepatomegaly, nephromegaly, hyperlipidemia, growth retardation, and long-term renal and liver disease.

How is Von Gierke's disease treated?

Treatment for Von Gierke's disease includes a carbohydrate balanced diet with frequent meals and nocturnal continuous tube feeding, liver transplant or hepatocytes transplantation, and gene therapy.

What are glycogen storage disorders?

Glycogen storage disorders are a group of inherited inborn errors of metabolism due to deficiency or dysfunction of enzymes involved in glycogen metabolism. They are confined primarily to the liver and muscle, but some cause more generalised pathology and affect other tissues such as the kidney, heart, and intestine.

What is Von Gierke's disease?

Von Gierke's disease, also known as Glycogen Storage Disease Type I, is an autosomal recessive disorder caused by deficiency or dysfunction of enzymes involved in glycogen metabolism. It is characterized by hypoglycemia, hepatomegaly, nephromegaly, hyperlipidemia, growth retardation, and long-term renal and liver disease.

What are the symptoms of Von Gierke's disease?

Patients with Von Gierke's disease have hypoglycemia, high levels of pyruvate and lactate in the blood (lactic acidemia), hepatomegaly, nephromegaly, hyperlipidemia, growth retardation, and long-term renal and liver disease.

How is Von Gierke's disease clinically diagnosed?

Clinical diagnosis of Von Gierke's disease is initially based on clinical and biochemical evaluation, confirmed by G6Pasa-aactivity in liver biopsy, and can be done by non-invasive investigations and mutation analysis.

What is the treatment for Von Gierke's disease?

Treatment for Von Gierke's disease includes a carbohydrate balanced diet with frequent meals and nocturnal continuous tube feeding, liver transplant or hepatocytes transplantation, and gene therapy (mice!) -CRISPR in future?

What is Von Gierke's disease?

Von Gierke's disease, also known as Glycogen Storage Disease Type I, is an autosomal recessive disorder caused by deficiency or dysfunction of enzymes involved in glycogen metabolism. It is characterized by hypoglycemia, hepatomegaly, nephromegaly, hyperlipidemia, growth retardation, and long-term renal and liver disease.

What are the symptoms of Von Gierke's disease?

Patients with Von Gierke's disease have hypoglycemia, high levels of pyruvate and lactate in the blood (lactic acidemia), hepatomegaly, nephromegaly, hyperlipidemia, growth retardation, and long-term renal and liver disease.

How is Von Gierke's disease clinically diagnosed?

Clinical diagnosis of Von Gierke's disease is initially based on clinical and biochemical evaluation, confirmed by G6Pasa-aactivity in liver biopsy, and can be done by non-invasive investigations and mutation analysis.

What is the treatment for Von Gierke's disease?

Treatment for Von Gierke's disease includes a carbohydrate balanced diet with frequent meals and nocturnal continuous tube feeding, liver transplant or hepatocytes transplantation, and gene therapy (mice!) -CRISPR in future?

What biochemical tests may be used to diagnose Von Gierke's disease?

Biochemical tests that can be used to diagnose Von Gierke's disease include measurement of glucose, lactate, and pyruvate levels in the blood, and enzyme assays, such as G6Pasa-aactivity in the liver, muscle, and red blood cells.

What are biochemical tests used to diagnose glycogen storage disorders?

Biochemical tests used to diagnose glycogen storage disorders include measurement of glucose, lactate, and pyruvate levels in the blood, and enzyme assays, such as G6Pasa-aactivity in the liver, muscle, and red blood cells.

What is the purpose of biochemical testing for glycogen storage disorders?

The purpose of biochemical testing for glycogen storage disorders is to identify the specific enzyme activity deficiency or dysfunction that is causing the disorder. This helps to guide treatment and follow-up care.

What are the types of biochemical tests used to diagnose glycogen storage disorders?

The types of biochemical tests used to diagnose glycogen storage disorders include enzyme assays, such as G6Pasa-aactivity in the liver, muscle, and red blood cells; measurement of glucose, lactate, and pyruvate levels in the blood; and molecular genetic testing.

How is molecular genetic testing used to diagnose glycogen storage disorders?

Molecular genetic testing is used to diagnose glycogen storage disorders by identifying the responsible gene mutations. This is done by sequencing the relevant genes or by performing targeted mutation analyses.

What is the significance of biochemical testing for glycogen storage disorders?

Biochemical testing for glycogen storage disorders provides important information about the type and severity of the disorder, which can help to guide treatment and follow-up care. It can also be used to differentiate between different types of glycogen storage disorders.

What is Pompe disease?

Pompe disease is an inherited glycogen storage disorder caused by deficiency of the lysosomal acid alpha-glucosidase enzyme. It is characterized by progressive muscle weakness and difficulty breathing.

What are the symptoms of Pompe disease?

The symptoms of Pompe disease typically begin in infancy and include progressive muscle weakness, cardiac abnormalities, respiratory problems, enlarged liver and spleen, feeding difficulties, and hypotonia.

How is Pompe disease diagnosed?

Pompe disease is diagnosed through a combination of clinical and laboratory tests, including measurement of lysosomal enzyme activity, genetic testing, and muscle biopsy.

What is the treatment for Pompe disease?

Treatment for Pompe disease includes enzyme replacement therapy with recombinant human acid alpha-glucosidase to replace the missing enzyme, physical and occupational therapy to improve muscle strength, and supportive care.

What is the prognosis for Pompe disease?

The prognosis for Pompe disease depends on the severity of the disease, the age at which treatment is started, and how well the patient responds to treatment. Early diagnosis and treatment can significantly improve the outcome.