• Mucopolysaccharidosis Type I

Disease at a Glance

Summary
Mucopolysaccharidosis type I (MPS I) is a condition that affects many parts of the body. MPS I is caused by genetic changes in the IDUA gene. These genetic changes lead to reduced levels or the complete lack of the IDUA enzyme. Without the proper amount of this enzyme, large sugar molecules called glycosaminoglycans (GAGs) accumulate within cells called lysosomes. This causes the lysosomes to increase in size, causing many different organs and tissues of the body to become enlarged. This leads to the medical problems seen in the condition. MPS I was once divided into three separate syndromes: Hurler syndrome, Hurler-Scheie syndrome, and Scheie syndrome, listed from most to least severe.
Estimated Number of People with this Disease
In the U.S. there may be between

300 to 3,000

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
Inherited Metabolic Disease;
Neurological Disease;
Birth Defect
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 Selected
Before Birth
Newborn Selected
Birth-4 weeks
Infant Selected
1-23 months
Child Selected
2-11 years
Adolescent Selected
12-18 years
Adult Selected
19-65 years
Older Adult Selected
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:
Cardiovascular System

56 Symptoms

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Cardiovascular System

The cardiovascular system is made up of the heart and blood vessels, including the arteries, veins, and capillaries. Common symptoms of problems in the cardiovascular system include high blood pressure, heart rate or heart rhythm problems, chest pain or discomfort, pain or tingling in the hands or feet, and fatigue. Diseases of the cardiovascular system may be diagnosed and treated by a cardiologist.
Medical Term

Abnormal aortic valve morphology

Frequency: Occasional
Description

Any abnormality of the aortic valve.

Any abnormality of the aortic valve.

Synonym

Abnormality of the aortic valve

Abnormality of the aortic valve

56 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