Because there's no cure for Hunter syndrome, treatment focuses on managing signs, symptoms and complications to provide some relief for your child as the disease progresses.
Although there's no cure for Hunter or other MPS syndromes, some treatments that are in their early stages have had some success by slowing the disease's progress and lessening its severity.
These emerging treatments include:
- Bone marrow transplantation. If a healthy donor matches your child's blood and tissue type, bone marrow transplantation can be used to treat some symptoms in milder forms of Hunter syndrome. Bone marrow is taken from the hip of the donor and transplanted to your child by injecting it into his or her veins (intravenously). This treatment can help ease the problems of breathing, mobility, and heart, liver and spleen function. It can also help prevent your child's mental regression. This treatment won't help with bone or vision problems.
Enzyme therapy. This treatment uses man-made or genetically engineered enzymes to replace your child's missing or defective enzymes and ease the disease symptoms. Called idursulfase (Elaprase), this treatment is given once a week through an intravenous line. Given early enough, enzyme replacement therapy may delay or prevent some of the symptoms of Hunter syndrome. It's unclear, however, if the improvements seen with this therapy are significant enough to raise quality of life for people with the disease. In addition, benefits in thinking and intelligence haven't been seen with enzyme replacement therapy.
Serious allergic reactions can occur during enzyme replacement therapy. Other possible side effects include headache, fever, skin reactions and high blood pressure. Side effects tend to lessen over time, however.
- Gene therapy. Replacing the chromosome responsible for producing the missing enzyme could theoretically cure Hunter syndrome, but much more research is needed.
Treatments for complications
Dec. 13, 2012
- Relief for respiratory complications. Removal of tonsils and adenoids can open up your child's airway and relieve sleep apnea. But as the disease progresses, tissues continue to thicken and these problems can come back. Breathing devices that use air pressure to keep the airway open — such as continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP) devices — can help with upper airway obstructions and sleep apnea. Keeping your child's airway open can also help avoid low blood oxygen levels (hypoxemia).
- Addressing heart complications. Your child's doctor will want to watch closely for cardiovascular complications, such as high blood pressure, heart murmur and leaky heart valves. If your child has severe cardiovascular problems, your doctor may recommend surgery to replace heart valves.
Treatment for skeletal and connective tissue problems. Because most children with Hunter syndrome don't heal well and often have complications after surgery, options are limited for addressing skeletal and connective tissue complications. For example, surgery to stabilize the spine using internal hardware is difficult when bones are fragile.
Your child's joint flexibility can be improved with physical therapy, which helps address stiffness and maintain function. However, physical therapy can't stop the progressive decline of joint motion. Your child may eventually need to use a wheelchair because of pain and limited stamina.
Surgery can repair hernias, but because of weakness in connective tissues, results usually aren't ideal. The procedure often needs to be repeated. One option is to manage your child's hernias with supportive trusses rather than surgery because of the risks of anesthesia and surgery.
- Managing neurological complications. Problems associated with the buildup of fluid and tissue around the brain and spinal cord are difficult to address because of the inherent risks in treating these parts of the body. Your child's doctor may recommend surgery to drain excess fluids or remove built-up tissue. If your child has seizures, your doctor may prescribe anticonvulsant medications.
- Managing behavioral problems. If your child develops abnormal behavior as a result of Hunter syndrome, providing a safe home environment is one of the most important ways you can manage this challenge. Treating behavior problems with medications has had limited success because most medications have side effects that can make other complications of the disease, such as respiratory problems, even worse.
- Addressing sleep issues. The sleep patterns of a child with Hunter syndrome become more and more disorganized. Medications including sedatives and especially melatonin can improve sleep. Keeping a strict bedtime schedule and making sure your child sleeps in a well-darkened room also can help. In addition, creating a safe environment in your child's bedroom — putting the mattress on the floor, padding the walls, removing all hard furniture, placing only soft, safe toys in the room — may help you rest easier if you know your child has less opportunity for injury.
- Scarpa, et al. Mucopolysaccharidosis type II: European recommendations for the diagnosis and multidisciplinary management of a rare disease. Orphanet Journal of Rare Diseases. 2011;6:1.
- Martin R, et al. Recognition and diagnosis of mucopolysaccharidosis II (Hunter syndrome). Pediatrics. 2008;121:e377.
- Mucopolysaccharidoses fact sheet. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/mucopolysaccharidoses/detail_mucopolysaccharidoses.htm. Accessed Oct. 11, 2012.
- Kakkis E, et al. Complications and management of the mucopolysaccharidoses. http://www.uptodate.com/ index. Accessed Sept. 21, 2012.
- Muenzer J, et al. Multidisciplinary management of Hunter syndrome. Pediatrics. 2009;124:e1228.
- Da Silva EMK, et al. Enzyme replacement therapy with idursulfase for mucopolysaccharidosis type II (Hunter syndrome). Cochrane Database of Systematic Reviews. 2011; 9:CD008185. http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD008185.pub2/abstract. Accessed Oct. 1, 2012.
- Valayannopoulos V, et al. Therapy for the mucopolysaccharidoses. Rheumatology. 2011;50:v49.
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