Hunter Syndrome (Mucopolysaccharidosis Type II) Treatment & Management

Updated: Apr 18, 2018
  • Author: Germaine L Defendi, MD, MS, FAAP; Chief Editor: Maria Descartes, MD  more...
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Treatment

Medical Care

Although no curative treatment for lysosomal storage disorders is available, numerous treatment options are becoming available to improve the quality of life for these patients. The relevant enzyme, iduronate sulfatase (IDS) in the case of MPS II, can be administered to patients as enzyme replacement therapy (ERT). [32, 33, 34]  Bone marrow transplantation (BMT) is another treatment modality. Factors that affect patient outcome using these treatment modalities include the type of MPS, the donor genotype (in the case of BMT), and the age and degree of clinical involvement at the start of ERT or BMT.

In order to identify patients who might benefit from treatment before irreversible organ damage occurs, metabolic newborn screening for these disorders is being developed. [35] Gene therapy is a promising but inadequately developed modality of treatment. Difficulties with vector selection and efficiency of delivery persist; thus, this therapy is still in the early stages of development.

BMT

A study published in Journal of Inherited Metabolic Diseases addressed the long-term follow-up of patients with MPS II following BMT. Of the 16 children with MPS II who had undergone BMT, 15 of them continued to show marked deterioration in their intellectual abilities. [36] All 15 children had intelligence quotients that were below 50. Some children showed improvement in their somatic symptoms, such as a decrease in the coarseness of their facial features and an increase in the range of motion in their joints. Hearing deficits were not shown to improve after BMT.

IN 2000, the use of umbilical cord blood transplantation from an unrelated donor to treat a patient with MSP IIB was attempted. [37]

ERT

See Medication.

Enzyme replacement therapy (ERT) can help make the disease more manageable; however, it is not a cure for MPSs.

In 2006, the US FDA granted marketing approval for idursulfase (Elaprase), the first FDA-approved ERT for the treatment of MPS II. Elaprase targets the replacement of iduronate-sulfatase (IDS), the enzyme deficient in patients with MPS II. It is administered as a weekly IV infusion. In patients aged 16 months to 5 years, no data are available to demonstrate improvement in disease-related symptoms or in long-term clinical outcome; however, treatment with idursulfase has reduced spleen volume in patients with MPS II. Elaprase has also shown to improve walking capacity in patients aged 5 years and older. The safety and efficacy of Elaprase have not been established in children younger than 16 months.

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Surgical Care

Many children with MPS II require surgical intervention for clinical complications of their disorder. These include intervention for chronic hydrocephalus, tracheostomy, nerve entrapment (carpal tunnel syndrome), abdominal wall hernias, and joint contractures.

Patients with MPS II should undergo anesthesia at a medical facility staffed with experienced and knowledgeable health care personnel. Complications can occur with airway management, postobstructive pulmonary edema, and reactive airway disease.

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Consultations

In 2008, the recognition and diagnosis of MPS II was reviewed in the American Academy of Pediatrics journal, Pediatrics. [38] This article clearly cited that the proper care for children with Hunter syndrome involves a multidisciplinary approach. The multidisciplinary team should include pediatricians, neurologists, orthopedists, otolaryngologists, ophthalmologists, audiologists, occupational and physical therapists, and geneticists and genetic counselors.

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