eMedicine Specialties > Pediatrics: Genetics and Metabolic Disease > Metabolic Diseases
Mucopolysaccharidosis Type VI: Treatment & Medication
Updated: Dec 11, 2008
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
Treatment
Medical Care
Patients with mucopolysaccharidosis type VI (MPS VI) require ongoing medical care from numerous subspecialists. In addition, patients should receive routine pediatric care, including immunizations. The US Food and Drug Administration (FDA)–approved enzyme replacement therapy with galsulfase (Naglazyme) has been shown to improve walking and stair-climbing capacity and to decrease urine glycosaminoglycan (GAG) levels in patients with MPS VI.
- Perform ongoing evaluations for the development of valvular cardiac disease. Such evaluations include annual echocardiograms. According to the American Heart Association (AHA) guidelines, patients should receive bacterial endocarditis prophylaxis before surgical or dental procedures.
- Many patients show evidence of restrictive airway disease, obstructive airway disease, or both. Conduct ongoing assessments for the development of clinically significant hypoventilation. Patients may benefit from oxygen or positive pressure therapy (continuous positive airway pressure [CPAP] or bilevel positive airway pressure [BIPAP]), especially when asleep if they have sleep apnea.
- Patients typically have contractures and hand deformities. A program of physical therapy may be beneficial in maintaining optimal function. Carpal tunnel syndrome may be present and asymptomatic and should be evaluated with nerve conduction on a regular basis.
- Patients who develop headache, vision change, or vomiting should be evaluated for increased intracranial pressure and hydrocephalus. Measuring intrathecal spinal fluid pressure to confirm increased intracranial pressure may be necessary.
Surgical Care
- Patients who develop clinically significant valvular heart disease may require valve replacement.
- Patients with obstructive airway disease sometimes benefit from tonsillectomy and adenoidectomy. Severe airway obstruction and hypoventilation may eventually require tracheostomy.
- Corneal transplants have been successful in restoring vision to patients with corneal clouding, although storage in the transplanted cornea may recur over time.
- Surgical decompression of the carpal tunnel to preserve median nerve function may be necessary.
- Neurosurgery may be required to place ventriculoperitoneal decompression shunts for hydrocephalus or increased intracranial pressure.
- Orthopedic surgery may be necessary to decompress the spinal cord or to stabilize the atlantoaxial junction.
- Patients often develop hip dysplasia and require hip replacement surgery
Consultations
- Geneticist: Refer all patients suspected of having an MPS to a medical geneticist. The geneticist is needed to provide definitive diagnosis and appropriate counseling of the family about recurrence risks.
- Cardiologist: Refer affected patients to a cardiologist because of the risk for valvular heart disease.
- Audiologist: Refer affected patients to an audiologist for periodic hearing evaluations because both conductive and sensorineural hearing loss can occur.
- Ophthalmologist: Obtain slitlamp and funduscopic examinations during the initial evaluation and then periodically thereafter. Corneal clouding can lead to significant visual impairment.
- Neurosurgeon or orthopedist: Spinal cord compression secondary to thickening of the dura in the cervical canal has been described. Spinal cord compression results in myelopathy, which may require surgical intervention.
- Pulmonologist: A pulmonologist should evaluate the patient regularly to identify airway obstruction, hypoventilation, or sleep apnea.
Diet
- No special dietary requirements are noted.
Activity
- Patients with MPS VI usually have some limitations on their level of activity because of contractures and joint stiffness.
- Patients with cardiac manifestations may be limited in their activity level.
Medication
Specific therapy for mucopolysaccharidosis type VI (MPS VI) is just beginning to emerge, with recent clinical trials showing benefit from a recombinant DNA glycoprotein enzyme replacement therapy.
Enzyme replacement therapy
Recombinant DNA variant of N -acetylgalactosamine 4-sulfatase has been shown to improve physical capabilities of individuals with MPS VI.
Galsulfase (Naglazyme)
Indicated for MPS VI, which is characterized by the absence or marked reduction of N -acetylgalactosamine 4-sulfatase; provides exogenous enzyme as treatment. Recombinant DNA glycoprotein (Chinese hamster ovary cell line) variant form of polymorphic human enzyme N -acetylgalactosamine 4-sulfatase. Clinical trials showed improvement in walking and stair-climbing capacity. Most patients in the clinical trials were pediatric patients; however, children <5 y were not included.
Adult
1 mg/kg IV infused over at least 4 h qwk; may extend infusion up to 20 h if infusion reactions occur
Pediatric
<5 years: Not established
>5 years: Administer as in adults
None reported
None known
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Nearly all patients develop antibodies to galsulfase (pretreat with antihistamine [eg, diphenhydramine] with or without antipyretics [eg, acetaminophen] 30-60 min prior to each infusion); severe infusion reactions have occurred despite pretreatment with antihistamines and antipyretics and may include angioneurotic edema, hypotension, dyspnea, bronchospasm, respiratory distress, apnea, and urticaria; common infusion-related reactions include fever, chills/rigor, headache, rash, and mild-to-moderate urticaria; nausea, vomiting, elevated blood pressure, retrosternal pain, abdominal pain, malaise, and joint pain may occur; initial infusion reactions may occur as late as week 55 of treatment; sedating antihistamines may cause sleep apnea; moderate-to-severe infusion-associated reactions can generally be managed by slowing infusion rate and providing corticosteroid pretreatment in the 24-h period before the infusion
More on Mucopolysaccharidosis Type VI |
| Overview: Mucopolysaccharidosis Type VI |
| Differential Diagnoses & Workup: Mucopolysaccharidosis Type VI |
 Treatment & Medication: Mucopolysaccharidosis Type VI |
| Follow-up: Mucopolysaccharidosis Type VI |
| References |
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References
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Further Reading
Keywords
Maroteaux-Lamy syndrome, mucopolysaccharidosis type VI, arylsulfatase B deficiency, polydystrophic dwarfism, type VI mucopolysaccharidosis, MPS, MPS VI, coarse facies, corneal clouding, organomegaly, joint stiffness, dysostosis multiplex, hernias, short stature, mental retardation, otitis media, hearing loss, chronic respiratory tract infections, sleep apnea, pulmonary hypertension, hydrocephalus, rapid-onset blindness, cardiac valve insufficiency, dwarfism, hepatosplenomegaly, macrocephaly, claw-hand deformities, hirsutism
