• Glycogen Storage Disease Type 6

Disease at a Glance

Summary
Glycogen storage disease type 6 (GSD6) is a genetic disease in which the liver cannot process sugar properly. The liver is responsible for breaking down a substance called glycogen. Glycogen is the stored form of sugar that is made by breaking down carbohydrates. When the liver cannot break down glycogen properly it causes a buildup that is damaging to the body. Symptoms of the disease usually begin in infancy or childhood and include low blood sugar (hypoglycemia), an enlarged liver (hepatomegaly), and an increase in the amount of lactic acid in the blood (lactic acidosis). These symptoms are especially likely to occur when an individual does not eat for a long time. Symptoms tend to improve as people with this disease get older. The disease is especially common in the Mennonite population. GSD6 is caused by genetic changes (changes) in the PYGL gene. The disease is inherited in an autosomal recessive manner. The diagnosis is made based on genetic testing of the PYGL gene. A liver biopsy that tests the function of liver glycogen phosphorylase may be necessary if the results of the genetic testing are inconclusive.
Resource(s) for Medical Professionals and Scientists on This Disease:
  • RareSource offers rare disease gene variant annotations and links to rare disease gene literature.

About Glycogen storage disease type 6

Many rare diseases have limited information. Currently GARD aims to provide the following information for this disease:

  • Population Estimate:This section is currently in development.
  • Symptoms:May start to appear as a Child.
  • Cause:This condition is caused by a change in the genetic material (DNA).
  • Organizations:Patient organizations are available to help find a specialist, or advocacy and support for this specific disease.
  • Categories:Inherited Metabolic DiseaseGenetic Disease
When Do Symptoms of Glycogen storage disease type 6 Begin?
Symptoms of this disease may start to appear as a Child.

The age symptoms may begin to appear differs between diseases. Symptoms may begin in a single age range, or during several age ranges. The symptoms from some diseases may begin at any age. Knowing when symptoms began to appear can help medical providers find the correct diagnosis.
Prenatal
Before Birth
Newborn
Birth-4 weeks
Infant
1-23 months
Child Selected
2-11 years
Adolescent
12-18 years
Adult
19-65 years
Older Adult
65+ years
Symptoms may start to appear as a Child.
This information comes from Orphanet

Symptoms

The number and severity of symptoms experienced may differ among people with this disease. Your experience may be different from others, and you should consult your primary care provider for more information.

This list is not all-inclusive, but the following symptoms have been linked to this disease:
Digestive System Digestive System

22 Symptoms

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List View
Tile View
List View

Digestive System

The digestive system is made up of the esophagus, stomach, intestines, liver, pancreas, and gallbladder. Common symptoms of problems in the digestive system include blood in the stool, changes in bowel habits, severe abdominal pain, unintentional weight loss, or heartburn. Diseases affecting the digestive system may be diagnosed and treated by a gastroenterologist (GI specialist).
Medical Term

Hepatomegaly

Frequency
Uncommon
Very frequent
Very frequent
Always
Description

Abnormally increased size of the liver.

Abnormally increased size of the liver.

Synonym

Enlarged liver

Enlarged liver

22 Symptoms
This information comes from the Human Phenotype Ontology (HPO)

Causes

Genetic Disease

Glycogen storage disease type 6 is a genetic disease, which means that it is caused by one or more genes not working correctly.

Disease-causing variants, or differences, in the following gene(s) are known to cause this disease: PYGL

What Is a Gene?

Understanding what genes are and how changes in genes may affect the body can help you on the journey to diagnosis and treatment of a genetic disease.

Genes are part of our DNA, the basic genetic material found in each of our body's cells. Cells are the building blocks of all living things and specialized cells form our body's organs and tissues. DNA is found in the nucleus of a cell and, in humans, is packaged into 23 pairs of chromosomes with the help of special proteins.

Each gene performs a different job in our cells. Some genes serve as the instructions to make proteins. Proteins are needed for the structure, function, and regulation of the body's cells, tissues, and organs. Some genes can turn other genes on or off. Others make RNA molecules that are involved in chemical reactions in the body.

Sources to Learn More: What Is a Gene? (MedlinePlus); What Are Proteins and What Do They Do? (MedlinePlus)Understanding what genes are and how changes in genes may affect the body can help you on the journey to diagnosis and treatment of a genetic disease.

Genes are part of our DNA, the basic genetic material found in each of our body's cells. Cells are the building blocks of all living things and specialized cells form our body's organs and tissues. DNA is found in the nucleus of a cell and, in humans, is packaged into 23 pairs of chromosomes with the help of special proteins.

Each gene performs a different job in our cells. Some genes serve as the instructions to make proteins. Proteins are needed for the structure, function, and regulation of the body's cells, tissues, and organs. Some genes can turn other genes on or off. Others make RNA molecules that are involved in chemical reactions in the body.

Sources to Learn More: What Is a Gene? (MedlinePlus); What Are Proteins and What Do They Do? (MedlinePlus)
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Inheritance

All individuals inherit two copies of most genes. The number of copies of a gene that need to have a disease-causing variant affects the way a disease is inherited. This disease is inherited in the following pattern(s):

Autosomal Recessive Inheritance

Autosomal means the gene is located on any chromosome except the X or Y chromosomes (sex chromosomes). Genes, like chromosomes, usually come in pairs. Recessive means that both copies of the responsible gene must have a disease-causing change (pathogenic variant) in order for a person to have the disease. Mutation is an older term that is still sometimes used to mean pathogenic variant.

A person who has an autosomal recessive disease receives a gene with a pathogenic variant from each of their parents. Each parent is a carrier which means they have a pathogenic variant in only one copy of the gene. Carriers of an autosomal recessive disease usually do not have any symptoms of the disease. When two carriers of an autosomal recessive disease have children, there is a 25% (1 in 4) chance to have a child who has the disease.Autosomal means the gene is located on any chromosome except the X or Y chromosomes (sex chromosomes). Genes, like chromosomes, usually come in pairs. Recessive means that both copies of the responsible gene must have a disease-causing change (pathogenic variant) in order for a person to have the disease. Mutation is an older term that is still sometimes used to mean pathogenic variant.

A person who has an autosomal recessive disease receives a gene with a pathogenic variant from each of their parents. Each parent is a carrier which means they have a pathogenic variant in only one copy of the gene. Carriers of an autosomal recessive disease usually do not have any symptoms of the disease. When two carriers of an autosomal recessive disease have children, there is a 25% (1 in 4) chance to have a child who has the disease.
Read More

Advocacy and Support Groups

How Can Patient Organizations Help?

Patient organizations can help patients and families connect. They build public awareness of the disease and are a driving force behind research to improve patients' lives. They may offer online and in-person resources to help people live well with their disease. Many collaborate with medical experts and researchers.

Services of patient organizations differ, but may include:

  • Ways to connect to others and share personal stories
  • Easy-to-read information
  • Up-to-date treatment and research information
  • Patient registries
  • Lists of specialists or specialty centers
  • Financial aid and travel resources

Please note: GARD provides organizations for informational purposes only and not as an endorsement of their services. Please contact an organization directly if you have questions about the information or resources it provides.

Patient Organizations

7 Organizations

Organization Name

Who They Serve

Helpful Links

Country

Association for Glycogen Storage Disease UK
People With

Glycogen Storage Disease Type 6

Helpful Links
Country

United Kingdom

Canadian Association for Glycogen Storage Disease
People With

Glycogen Storage Disease Type 6

Helpful Links
Country

Canada

Metabolic Support UK
People With

Glycogen Storage Disease Type 6

Helpful Links
Country

United Kingdom

EveryLife Foundation for Rare Diseases
People With

Rare Diseases

Helpful Links
Country

United States

Genetic Alliance
People With

Rare Diseases

Helpful Links
Country

United States

Global Genes
People With

Rare Diseases

Helpful Links
Country

United States

National Organization for Rare Disorders
People With

Rare Diseases

Helpful Links
Country

United States

Participating in Clinical Studies

Clinical studies are part of clinical research and at the heart of all medical advances, including rare diseases. Participating in research helps researchers ultimately uncover better ways to treat, prevent, diagnose, and understand human diseases.

What Are Clinical Studies?

Clinical studies are medical research involving people as participants. There are two main types of clinical studies:

  1. Clinical trials determine if a new test or treatment for a disease is effective and safe by comparing groups receiving different tests/treatments.
  2. Observational studies involve recording changes over time among a specific group of people in their natural settings.
Learn more about the different types of clinical studies, consent forms, questions you should ask before participating in clinical studies, and the difference between research and medical treatment.

Why Participate in Clinical Studies?

People participate in clinical trials for a variety of reasons. Participants with a disease may participate to help others, but also to possibly receive the newest treatment and additional care from clinical study staff. Healthy volunteers may also participate to help others and to contribute to moving science forward.

How Do You Find the Right Clinical Study?

To find the right clinical study we recommend you:

  • Use ClincalTrials.gov button below to search for studies by disease, terms, or country.
  • Consult doctors, other trusted medical professionals, and patient organizations.
  • Enroll in databases to allow researchers from participating institutions to find you.

What if There Are No Available Clinical Studies?

ResearchMatch helps connect people interested in research studies with researchers from top medical centers across the United States. Anyone from the U.S. can register with this free program funded by NIH. Researchers from participating institutions use the database to search for and invite patients or healthy volunteers who meet their study criteria to participate.

What Are Clinical Studies?

Clinical studies are medical research involving people as participants. There are two main types of clinical studies:

  1. Clinical trials determine if a new test or treatment for a disease is effective and safe by comparing groups receiving different tests/treatments.
  2. Observational studies involve recording changes over time among a specific group of people in their natural settings.
Learn more about the different types of clinical studies, consent forms, questions you should ask before participating in clinical studies, and the difference between research and medical treatment.

Why Participate in Clinical Studies?

People participate in clinical trials for a variety of reasons. Participants with a disease may participate to help others, but also to possibly receive the newest treatment and additional care from clinical study staff. Healthy volunteers may also participate to help others and to contribute to moving science forward.

How Do You Find the Right Clinical Study?

To find the right clinical study we recommend you:

  • Use ClincalTrials.gov button below to search for studies by disease, terms, or country.
  • Consult doctors, other trusted medical professionals, and patient organizations.
  • Enroll in databases to allow researchers from participating institutions to find you.

What if There Are No Available Clinical Studies?

ResearchMatch helps connect people interested in research studies with researchers from top medical centers across the United States. Anyone from the U.S. can register with this free program funded by NIH. Researchers from participating institutions use the database to search for and invite patients or healthy volunteers who meet their study criteria to participate.

ClinicalTrials.gov, an affiliate of NIH, provides current information on clinical research studies in the United States and abroad. Talk to a trusted doctor before choosing to participate in any clinical study. We recommend checking this site often and searching for studies with related terms/synonyms to improve results.
Please contact GARD if you need help finding additional information or resources on rare diseases, including clinical studies. Our Information Specialists are available to you by phone or by filling out our contact form. Note, GARD cannot enroll individuals in clinical studies.
ClinicalTrials.gov, an affiliate of NIH, provides current information on clinical research studies in the United States and abroad. Talk to a trusted doctor before choosing to participate in any clinical study. We recommend checking this site often and searching for studies with related terms/synonyms to improve results.
Please contact GARD if you need help finding additional information or resources on rare diseases, including clinical studies. Our Information Specialists are available to you by phone or by filling out our contact form. Note, GARD cannot enroll individuals in clinical studies.

Learn about symptoms, cause, support, and research for a rare disease. 

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Take steps toward getting a diagnosis by working with your doctor, finding the right specialists, and coordinating medical care.

Last Updated: February 2023