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Hunter syndrome in Adult
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Hunter syndrome in Adult

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Contributors: Jennifer Vermilion MD, Jamie Adams MD, Richard L. Barbano MD, PhD
Other Resources UpToDate PubMed


Hunter syndrome (mucopolysaccharidosis II, or MPS II) is an X-linked recessive lysosomal storage disease caused by a deficiency in iduronate-2-sulfatase that leads to an accumulation of heparan sulfate and dermatan sulfate in various organs. It is a rare disorder, with an estimated prevalence of 1 in 170 000 live births. There is a higher incidence in the Ashkenazi and Sephardic Jewish populations. Hunter syndrome predominantly affects males but has been described in females, often secondary to skewed X chromosome inactivation.

There is a broad phenotypic spectrum of severity. The severe form is most common, with symptom onset typically between 2 and 4 years of age. Signs and symptoms include distinct, coarse facial features, intellectual disability, developmental delay, hepatosplenomegaly, skeletal deformities, joint stiffness, carpal tunnel syndrome, vision changes, recurrent ear infections, and progressive hearing loss. Hydrocephalus or spinal cord compression may develop. Patients typically develop valvular heart disease and obstructive airway disease.

Average life expectancy is about 10-15 years. The attenuated form of Hunter syndrome may have minimal neurologic symptoms, and these patients often have normal intelligence.

For more information, see OMIM.


E76.1 – Mucopolysaccharidosis, type II

70737009 – Mucopolysaccharidosis type II

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Diagnostic Pearls

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Differential Diagnosis & Pitfalls

  • MPS I or MPS VII – As with Hunter syndrome, these patients excrete dermatan sulfate and heparan sulfate in their urine. See Hurler syndrome (MPS I-H).
  • MPS III-VI – Urinary GAG composition can help distinguish these from Hunter syndrome. See Maroteaux-Lamy syndrome (MPS VI).
  • Multiple sulfatase deficiency
  • Mucolipidosis type II
  • Mucolipidosis type III

Best Tests

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Management Pearls

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Last Reviewed: 10/24/2018
Last Updated: 11/07/2018
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Hunter syndrome in Adult
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Hunter syndrome : Hepatosplenomegaly, Hearing loss, Hoarseness, Joint stiffness, Developmental delay
Clinical image of Hunter syndrome
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