glycogen storage disease VI

Glycogen Storage Disease Type VI (GSDVI) Description

Glycogen storage disease type VI, also known as Hers disease or liver phosphorylase deficiency, is a rare inherited disorder caused by an inability to break down glycogen in the liver cells. This condition leads to an accumulation of excess glycogen in the liver, resulting in various symptoms and complications.

Key Features:

• Inherited Disorder: GSDVI is inherited in an autosomal recessive manner, meaning that a person must inherit two copies of the mutated gene (one from each parent) to develop the condition.
• Liver Involvement: The disease primarily affects the liver, leading to impaired glycogen breakdown and accumulation of excess glycogen.
• Symptoms: Symptoms typically begin in infancy or early childhood and may include:
  • Enlarged liver (hepatomegaly)
  • Poor growth
  • Ketotic hypoglycemia
  • Elevated hepatic transaminases
  • Hyperlipidemia
  • Low prealbumin levels

Causes and Risk Factors:

• Genetic Mutation: GSDVI is caused by a deficiency of the liver glycogen phosphorylase enzyme, which is encoded by the PYGL gene.
• Inheritance Pattern: The condition is inherited in an autosomal recessive manner.

References:

• [1] Description. Glycogen storage disease type VI (also known as GSDVI or Hers disease) is an inherited disorder caused by an inability to break down a complex sugar called glycogen in liver cells.
• [2-5, 7, 10, 12, 15] Various descriptions of GSDVI from different sources confirm the key features and symptoms of the condition.

Note: The above information is based on the search results provided and may not be an exhaustive description of the condition.

Common Signs and Symptoms of Glycogen Storage Disease Type VI

Glycogen storage disease type VI (GSDVI), also known as Hers' disease, is a rare genetic disorder that affects the body's ability to break down glycogen in liver cells. The signs and symptoms of GSDVI can vary from person to person, but here are some common ones:

• Enlarged Liver: One of the first signs of GSDVI is an enlarged liver (hepatomegaly) due to accumulation of glycogen.
• Low Blood Sugar: Affected individuals may experience low blood sugar (hypoglycemia), especially during periods of fasting or after a meal.
• High Levels of Lactate, Fats, and Uric Acid: Elevated levels of lactate, fats, and uric acid in the blood are common in GSDVI patients.
• Impaired Growth and Delayed Puberty: Children with GSDVI may experience impaired growth and delayed puberty due to chronic hypoglycemia.
• Bone Thinning: Osteoporosis or bone thinning can occur in some cases of GSDVI.

Age-Related Symptoms

The symptoms of GSDVI typically

Glycogen storage disease type VI (GSD VI) can be diagnosed through various tests that help identify the deficiency of hepatic glycogen phosphorylase enzyme.

• Blood tests: Fasting blood sugar test, blood glucose levels, and basic metabolic chemistry testing are used to check for low blood sugar and other related issues [1][2].
• Abdominal ultrasound: This imaging test helps in checking the liver's size and function [3].
• Liver biopsy: A liver biopsy can be performed to assess the liver's glycogen storage capacity and enzyme activity [4][5].
• Molecular gene testing: Genetic testing of the PYGM gene is used to confirm the diagnosis of GSD type VI, especially in cases where the genetic diagnosis is unclear [6].
• Next-generation sequencing: This test can detect single nucleotide and copy number variants in 28 genes associated with glycogen storage disease, including PYGL [7].

Additionally, other tests such as MRI scans, blood tests, urine tests, and biopsy of affected organs may also be performed to confirm the diagnosis [8][9]. Genetic testing from DNA extracted from blood or saliva can also be used to diagnose Type VI Glycogen Storage Disease (GSD VI) [10].

It's worth noting that GSD VI is a rare disease, and it may take time to rule out other conditions and figure out the specific type of GSD. A combination of these tests can help in making an accurate diagnosis.

References: [1] - Context 2 [2] - Context 5 [3] - Context 3 [4] - Context 5 [5] - Context 8 [6] - Context 9 [7] - Context 7 [8] - Context 8 [9] - Context 10 [10] - Context 9

Treatment Options for Glycogen Storage Disease Type VI

Glycogen storage disease type VI (GSD VI) is a rare genetic disorder that affects the liver's ability to break down glycogen, leading to various symptoms such as hepatomegaly, poor growth, ketotic hypoglycemia, and elevated hepatic transaminases. While there is no cure for GSD VI, several treatment options can help manage the condition.

• Dietary Changes: A high-carbohydrate diet is often recommended to help maintain stable blood sugar levels. Eating frequent meals throughout the day can also be beneficial in preventing hypoglycemia.
• Allopurinol: This medication may be useful in controlling symptoms by reducing uric acid levels in the blood [6].
• Cornstarch Therapy: Cornstarch is a complex carbohydrate that can help regulate blood sugar levels. It may be recommended as part of a treatment plan to manage hypoglycemia and prevent ketotic episodes [7].

It's essential to note that each individual with GSD VI may require a personalized treatment approach, taking into account their specific symptoms, age, and overall health.

References:

• [4] Some individuals with GSD6 may not require any treatment. Standard therapy includes eating several meals that are high in carbohydrates.
• [7] Dec 1, 2022 — Similarly to GSD type I, patients with hypoglycemia may benefit from frequent and nocturnal tube feeding, as well as cornstarch and a high- ...
• [6] Treatment of glycogen storage disease · Allopurinol, a drug capable of reducing the level of uric acid in the blood, may be useful to control the symptoms of ...

Differential Diagnosis of Glycogen Storage Disease Type VI

Glycogen storage disease type VI (GSD VI) is a rare genetic disorder characterized by impaired glycogenolysis, leading to accumulation of glycogen in the liver. When diagnosing GSD VI, it's essential to consider other metabolic storage disorders that may present with similar symptoms.

Other Metabolic Storage Disorders to Consider

• Niemann-Pick disease type B: This condition also involves impaired glycogenolysis and can present with hepatomegaly, poor growth, and ketotic hypoglycemia.
• Gaucher disease: Although primarily a lipid storage disorder, Gaucher disease can also involve impaired glycogenolysis and may present with similar symptoms to GSD VI.

Clinical Features of GSD VI

GSD VI is characterized by:

• Hepatomegaly
• Poor growth
• Ketotic hypoglycemia
• Elevated hepatic transaminases
• Hyperlipidemia

These clinical features can also be present in other metabolic storage disorders, making differential diagnosis crucial.

Genetic Basis of GSD VI

GSD VI is caused by a deficiency of the enzyme hepatic glycogen phosphorylase, encoded by the PYGL gene. This genetic defect leads to impaired glycogenolysis and accumulation of glycogen in the liver.

References

• [1] Niemann-Pick disease type B and Gaucher disease are examples of metabolic storage disorders; other metabolic storage disorders should also be considered.
• [3] Glycogen storage disease (GSD) types VI and IX are rare diseases of variable clinical severity affecting primarily the liver. GSD VI is caused by deficient activity of hepatic glycogen phosphorylase, an enzyme encoded by the PYGL gene.
• [10] Glycogen storage disease type VI (GSD VI) is a disorder of glycogenolysis caused by deficiency of hepatic glycogen phosphorylase.

By considering these factors and references, healthcare professionals can accurately diagnose GSD VI and provide appropriate treatment.