National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Mucopolysaccharidosis type II


Other Names:
MPS II; Attenuated MPS (subtype; formerly known as mild MPS II); Severe MPS II; MPS II; Attenuated MPS (subtype; formerly known as mild MPS II); Severe MPS II; Hunter syndrome; Iduronate 2-sulfatase deficiency; I2S deficiency; MPS 2 See More
Categories:
This disease is grouped under:
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]
Last updated: 6/20/2016

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.

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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 ] 		0000718
Arrhythmia
Abnormal heart rate
Heart rhythm disorders
Irregular heart beat
Irregular heartbeat
[ more ] 		0011675
Hypertension 0000822
Impulsivity
Impulsive
0100710
Large central visual field defect
Large central loss of field of vision
0001129
Oppositional defiant disorder 0010865
Peripheral arterial stenosis 0004950
Seizure 0001250
Stereotypy
Repetitive movements
Repetitive or self-injurious behavior
[ more ] 		0000733
Percent of people who have these symptoms is not available through HPO
Abnormal heart valve morphology 0001654
Asthma 0002099
Cervical cord compression 0002341
Congestive heart failure
Cardiac failure
Cardiac failures
Heart failure
[ more ] 		0001635
Delayed eruption of teeth
Delayed eruption
Delayed teeth eruption
Delayed tooth eruption
Eruption, delayed
Late eruption of teeth
Late tooth eruption
[ more ] 		0000684
Dermatan sulfate excretion in urine 0008301
Diarrhea
Watery stool
0002014
Dolichocephaly
Long, narrow head
Tall and narrow skull
[ more ] 		0000268
Flexion contracture
Flexed joint that cannot be straightened
0001371
Hearing impairment
Deafness
Hearing defect
[ more ] 		0000365
Heparan sulfate excretion in urine 0002159
Hydrocephalus
Too much cerebrospinal fluid in the brain
0000238
Hypertrichosis 0000998
Intellectual disability, profound
IQ less than 20
0002187
Intestinal pseudo-obstruction 0004389
Kyphosis
Hunched back
Round back
[ more ] 		0002808
Mild short stature 0003502
Neurodegeneration
Ongoing loss of nerve cells
0002180
Obstructive sleep apnea 0002870
Pes cavus
High-arched foot
0001761
Ptosis
Drooping upper eyelid
0000508
Recurrent otitis media
Recurrent middle ear infection
0000403
Scaphocephaly 0030799
Severe short stature
Dwarfism
Proportionate dwarfism
Short stature, severe
[ more ] 		0003510
Short neck
Decreased length of neck
0000470
Split hand
Claw hand
Claw hand deformities
Claw hands
Claw-hand deformities
Split-hand
[ more ] 		0001171
Thick lower lip vermilion
Increased volume of lower lip
Plump lower lip
Prominent lower lip
[ more ] 		0000179
Tracheobronchomalacia 0002786
Urinary glycosaminoglycan excretion 0003541
Widely spaced teeth
Wide-spaced teeth
Widely-spaced teeth
[ more ] 		0000687
X-linked recessive inheritance 0001419
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Last updated: 7/1/2020
MPS II is inherited in an X-linked recessive pattern, which means that this conditions occurs almost exclusively in males. Females are generally unaffected carriers of this condition. In a family with more than one affected individual, the mother of the affected males must be a carrier. When a carrier female has a child, there is a 25% (1 in 4) chance that she will have a affected son.[1]
Last updated: 9/20/2013
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.

 

Last updated: 9/20/2013

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.

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
Differential diagnoses include mucopolysaccharidosis type 1, 6, 7; sialidosis type 2; mucolipidosis type 2 and 3; and multiple sulfatase deficiency.
Visit the Orphanet disease page for more information.

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Mucopolysaccharidosis type II. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Patient Registry

  • The Lysosomal Disease Network is a team of doctors, nurses, research coordinators, and research labs throughout the U.S., working together to improve the lives of people with this condition through research. The Lysosomal Disease Network has a registry for patients who wish to be contacted about clinical research opportunities.

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

Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.

Financial Resources

  • National Organization for Rare Disorders (NORD) has Disease-Specific Assistance Programs designed to help patients with out-of-pocket costs such as monthly insurance premiums or deductibles. In addition, some programs may provide financial assistance for additional expenses related to a patient's diagnosis such as travel to see a specialist.
  • The Social Security Administration has included this condition in their Compassionate Allowances Initiative. This initiative speeds up the processing of disability claims for applicants with certain medical conditions that cause severe disability. More information about Compassionate Allowances and applying for Social Security disability is available online.

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.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • I had two brothers with the severe form of Hunter syndrome and both have passed away.  I was never tested to see if I am a carrier, and now my daughter would like to know if she is a carrier. Is there a definitive test to determine if one is a carrier? Who do we contact to be tested? See answer


  1. Martin RA. Mucopolysaccharidosis Type II. Gene Reviews. March 26, 2015; http://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.