DISEASE SCANNER

Global Incurable Diseases Tracker

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Metabolic Disorder

Hunter Syndrome (Mucopolysaccharidosis Type II)

HIGH SEVERITY

An X-linked lysosomal storage disorder caused by deficiency of iduronate-2-sulfatase, leading to accumulation of glycosaminoglycans (GAGs). Affects multiple organ systems including skeleton, heart, and brain. Only MPS disorder that is X-linked. Ranges from severe (with cognitive decline) to attenuated (without cognitive involvement).

Global Affected

50.0K

Countries

19

Symptoms

Coarse facial features
Hepatosplenomegaly
Skeletal abnormalities (dysostosis multiplex)
Joint stiffness
Cardiac valve disease
Respiratory problems
Developmental delay (severe form)
Behavioral problems

Treatment Options

Enzyme replacement therapy (idursulfase)
Hematopoietic stem cell transplant
Intrathecal ERT (investigational)
Carpal tunnel surgery
Cardiac valve replacement
Positive airway pressure for sleep apnea
Physical therapy
Behavioral interventions

Risk Factors

1X-linked inheritance
2IDS gene mutations
3Family history of Hunter syndrome
4Male gender (primarily affected)
5New mutations (in many cases)

Diagnostic Methods

  • 1Iduronate-2-sulfatase enzyme assay
  • 2Urinary GAG analysis
  • 3Genetic testing for IDS mutations
  • 4Skeletal survey (X-rays)
  • 5Echocardiogram
  • 6Sleep study
  • 7Neuropsychological testing

Prognosis

Severe form: Death in first or second decade, usually from cardiac or respiratory complications. Attenuated form: Normal intelligence, survival into adulthood possible with ERT. ERT improves somatic symptoms but not neurological decline in severe form. Quality of life significantly affected. Regular multidisciplinary care essential. Life expectancy improving with modern management but still reduced.

Prevention

  • Genetic counseling
  • Carrier detection in female relatives
  • Prenatal diagnosis
  • Preimplantation genetic diagnosis
  • Early treatment initiation
  • Regular monitoring

Research Status

Enzyme replacement therapy (idursulfase) available but does not cross blood-brain barrier. Hematopoietic stem cell transplant may help neurological symptoms. Intrathecal ERT being studied. Gene therapy research ongoing.

Affected Countries

United StatesUnited KingdomCanadaAustraliaGermanyFranceItalySpainJapanBrazilMexicoNetherlandsSwedenNorwayFinlandIndiaChinaSouth KoreaSouth Africa

Sources

  • https://www.ncbi.nlm.nih.gov/books/NBK1274
  • https://www.mayoclinic.org/diseases-conditions/mucopolysaccharidosis
  • https://rarediseases.org/rare-diseases/mucopolysaccharidosis-type-ii

Medical Disclaimer

This information is for educational purposes only. Always consult healthcare professionals for medical advice, diagnosis, and treatment.