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Disease Profile

Mucopolysaccharidosis type II

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.
1-9 / 1 000 000

331 - 2,979

US Estimated

1-9 / 1 000 000

514 - 4,622

Europe Estimated

Age of onset

Childhood

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ICD-10

E76.1

Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

MPS II; Attenuated MPS (subtype; formerly known as mild MPS II); Severe MPS II;

Categories

Metabolic disorders

Summary

Mucopolysaccharidosis II (MPS II) is an inherited disorder of carbohydrate metabolism that occurs almost exclusively in males. It is characterized by distinctive facial features, a large head, hydrocephalus, enlargement of the liver and spleen (hepatosplenomegaly), umbilical or inguinal hernia, and hearing loss. Individuals with this condition may additionally have joint deformities and heart abnormalities involving the valves. MPS II is caused by mutations in the IDS gene and is inherited in an X-linked manner.[1]

There is a wide range in severity of symptoms present in individuals with MPS II. Previously, MPS II was classified as severe and attenuated based on severity. More recently, the terms slowly progressive and early progressive have been suggested. While both types affect many different parts of the body, people with the severe type also experience a decline in intellectual function and a more rapid disease progression. The life expectancy for people with the severe type is 10 to 20 years. Individuals with the less severe type typically live into adulthood and intelligence is not affected. Treatment is focused on managing the signs and symptoms present in each individual.[1][2]

Symptoms

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Coarse facial features
Coarse facial appearance
0000280
Limitation of joint mobility
Decreased joint mobility
Decreased mobility of joints
Limited joint mobility
Limited joint motion

[ more ]

0001376
Macrocephaly
Increased size of skull
Large head
Large head circumference

[ more ]

0000256
Short stature
Decreased body height
Small stature

[ more ]

0004322
30%-79% of people have these symptoms
Chronic diarrhea
0002028
Conductive hearing impairment
Conductive deafness
Conductive hearing loss

[ more ]

0000405
Contractures of the large joints
0005781
Decreased nerve conduction velocity
0000762
Developmental regression
Loss of developmental milestones
Mental deterioration in childhood

[ more ]

0002376
Dysostosis multiplex
0000943
Enlarged tonsils
0030812
Flexion contracture of digit
0030044
Full cheeks
Apple cheeks
Big cheeks
Increased size of cheeks
Large cheeks

[ more ]

0000293
Gingival overgrowth
Gum enlargement
0000212
Hepatomegaly
Enlarged liver
0002240
Hoarse voice
Hoarseness
Husky voice

[ more ]

0001609
Inguinal hernia
0000023
Irregularity of vertebral bodies
0004582
Macroglossia
Abnormally large tongue
Increased size of tongue
Large tongue

[ more ]

0000158
Peripheral visual field loss
Loss of peripheral vision
0007994
Progressive neurologic deterioration
Worsening neurological symptoms
0002344
Recurrent ear infections
Frequent ear infections
0410018
Recurrent upper respiratory tract infections
Recurrent colds
0002788
Retinal degeneration
Retina degeneration
0000546
Retinopathy
Noninflammatory retina disease
0000488
Sensorineural hearing impairment
0000407
Short attention span
Poor attention span
Problem paying attention

[ more ]

0000736
Sleep apnea
Pauses in breathing while sleeping
0010535
Sleep-wake cycle disturbance
0006979
Splenomegaly
Increased spleen size
0001744
Thick vermilion border
Full lips
Increased volume of lip
Plump lips
Prominent lips
Thick lips

[ more ]

0012471
Umbilical hernia
0001537
5%-29% of people have these symptoms
Abnormal aortic morphology
0001679
Abnormal epiphyseal ossification
0010656
Abnormal foveal morphology
0000493
Abnormal full-field electroretinogram
0030466
Abnormal mitral valve morphology
0001633
Abnormal nasal mucus secretion
0031416
Abnormal pulmonary valve morphology
0001641
Abnormal tricuspid valve morphology
0001702
Abnormality of retinal pigmentation
0007703
Cardiomyopathy
Disease of the heart muscle
0001638
Communicating hydrocephalus
0001334
Constrictive median neuropathy
0012185
Corneal opacity
0007957
Global developmental delay
0001263
Hip dysplasia
0001385
Hip osteoarthritis
0008843
Hyperactivity
More active than typical
0000752
Muscle stiffness
0003552
Nyctalopia
Night blindness
Night-blindness
Poor night vision

[ more ]

0000662
Optic atrophy
0000648
Otosclerosis
0000362
Papilledema
0001085
Prominent supraorbital ridges
Prominent brow
0000336
Spinal cord compression
Pressure on spinal cord
0002176
Temporomandibular joint ankylosis
Freezing of jaw joint
0012478
Upper airway obstruction
0002781
Wide nasal bridge
Broad nasal bridge
Broad nasal root
Broadened nasal bridge
Increased breadth of bridge of nose
Increased breadth of nasal bridge
Increased width of bridge of nose
Increased width of nasal bridge
Nasal bridge broad
Wide bridge of nose
Widened nasal bridge

[ more ]

0000431
Wide nose
Broad nose
Increased breadth of nose
Increased nasal breadth
Increased nasal width
Increased width of nose

[ more ]

0000445
1%-4% of people have these symptoms
Abnormal temper tantrums
0025160
Aggressive behavior
Aggression
Aggressive behaviour
Aggressiveness

[ more

Diagnosis

Yes, carrier testing for MPS II is available. Testing usually begins with an affected male relative, if one is available for testing, to determine the disease-causing mutation. If there is not living affected male relative, testing possible female carriers involves a type of genetic testing called sequence analysis. This test requires a small blood sample and reads through the genetic code of the IDS gene looking for errors. If a mutation is not found using sequence analysis, then two other tests can be performed to look for mutations that cause MPS II. Genetic testing detects most of the mutations that cause MPS II, but may not detect all mutations that cause this condition Therefore, testing cannot definitively determine that a person is not a carrier for MPS II.[1]

The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. Click here to link directly to a list of labs conducting carrier screening for MPS II. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

 

Treatment

The resources below provide information about treatment options for this condition. If you have questions about which treatment is right for you, talk to your healthcare professional.

Management Guidelines

  • Project OrphanAnesthesia is a project whose aim is to create peer-reviewed, readily accessible guidelines for patients with rare diseases and for the anesthesiologists caring for them. The project is a collaborative effort of the German Society of Anesthesiology and Intensive Care, Orphanet, the European Society of Pediatric Anesthesia, anesthetists and rare disease experts with the aim to contribute to patient safety.

    FDA-Approved Treatments

    The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition. Learn more orphan products.

    Organizations

    Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

    Organizations Supporting this Disease

      Learn more

      These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

      Where to Start

        In-Depth Information

        • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
        • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
        • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
        • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
        • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
        • PubMed is a searchable database of medical literature and lists journal articles that discuss Mucopolysaccharidosis type II. Click on the link to view a sample search on this topic.

          References

          1. Martin RA. Mucopolysaccharidosis Type II. Gene Reviews. March 26, 2015; https://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&part=hunter.
          2. Mucopolysaccharidoses Fact Sheet. National Institute of Neurological Disorders and Stroke (NINDS). February 23, 2016; https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Mucopolysaccharidoses-Fact-Sheet.

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