• Glycogen Storage Disease Type 1a

Disease at a Glance

Summary
Glycogen storage disease type 1 is an inherited disorder caused by the buildup of a complex sugar called glycogen in the body's cells. The accumulation of glycogen in certain organs and tissues, especially the liver, kidneys, and small intestines, impairs their ability to function normally. These types are known as glycogen storage disease type IA and glycogen storage disease type IB. Glycogen storage disease type 1A is characterized by growth retardation leading to short stature and accumulation of glycogen and fat in the liver and kidneys. Although some newborns present with severe hypoglycemia, it is more common for infants to present at age three to four months with hepatomegaly, lactic acidosis, hyperuricemia, hyperlipidemia, and/or hypoglycemic seizures. Xanthoma and diarrhea may be present. Impaired platelet function can lead to a bleeding tendency, making epistaxis a frequent problem. Glycogen storage disease type 1A is caused by the deficiency of glucose-6-phosphatase (G6Pase) catalytic activity which results from genetic changes in the G6PC gene. This condition is inherited in an autosomal recessive pattern.
Estimated Number of People with this Disease
In the U.S. there may be between

3,000 to 30,000

What Information Does GARD Have For This Disease?

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

*Data may be currently unavailable to GARD at this time.
Categories
Kidney Disease;
Inherited Metabolic Disease;
Liver Disease
When do symptoms of this disease begin?
The most common ages for symptoms of a disease to begin is called age of onset. Age of onset can vary for different diseases and may be used by a doctor to determine the diagnosis. For some diseases, symptoms may begin in a single age range or several age ranges. For other diseases, symptoms may begin any time during a person's life.
Prenatal
Before Birth
Newborn Selected
Birth-4 weeks
Infant Selected
1-23 months
Child
2-11 years
Adolescent
12-18 years
Adult
19-65 years
Older Adult
65+ years
The common ages for symptoms to begin in this disease are shown above by the colored icon(s).
This information comes from Orphanet

Symptoms

These symptoms may be different from person to person. Some people may have more symptoms than others and symptoms can range from mild to severe. This list does not include every symptom.
This disease might cause these symptoms:
Nervous System

8 Symptoms

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Tile View
List View

Nervous System

The nervous system is made up of the brain, spinal cord, and nerves. Common symptoms of problems in the nervous system include trouble moving, speaking, swallowing, breathing, or learning. Problems with memory, senses, or mood may also occur. Nervous system diseases are usually diagnosed and treated by neurologists.
Medical Term

Cognitive impairment

Frequency: Very frequent
Description

Abnormal cognition with deficits in thinking, reasoning, or remembering.

Abnormal cognition with deficits in thinking, reasoning, or remembering.

Synonym

Intellectual impairment

Intellectual impairment

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

Causes

This section is currently in development. 

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):

Questions:

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.
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Next Steps

Talking with the Medical Team

Good communication between the patient, family, and medical team can lead to an accurate diagnosis. In addition, health care decisions can be made together which improves the patient’s well-being and quality of life.

Describing Symptoms

Describe details about the symptoms. Because there may be many different causes for a single symptom, it is best not to make a conclusion about the diagnosis. The detailed descriptions help the medical provider determine the correct diagnosis.

To help describe a symptom:

  • Use a smartphone or a notebook to record each symptom before the appointment
  • Describe each symptom by answering the following questions:
    • When did the symptom start?
    • How often does it happen?
    • Does anything make it better or worse?
  • Tell the medical team whether any symptoms affect daily activities

Preparing for the First Visit

Working with a medical team to find a diagnosis can be a long process that will require more than one appointment. Make better health decisions by being prepared for the first visit with each member of the medical team.

    Make informed decisions about health care: 
    • Prepare a list of questions and concerns before the appointment
    • List the most important questions first, not all questions may be answered in the first visit
    • Ask questions about symptoms, possible diagnoses, tests, and treatment options
    For future appointments:
    • Discuss what was not addressed at the last visit
    • Discuss changes in the quality of life for the patient, family, and caregivers
    • Discuss health goals and other issues in the patient’s and family’s life that may affect the health care decisions
    Take notes during the appointments to help remember what was discussed.

    Next: Diagnosis & Treatment

    Last Updated: Nov. 8, 2021