Multidisciplinary Management of Hunter Syndrome

Abstract

Hunter syndrome is a rare, X-linked disorder caused by a deficiency of the lysosomal enzyme iduronate-2-sulfatase. In the absence of sufficient enzyme activity, glycosaminoglycans accumulate in the lysosomes of many tissues and organs and contribute to the multisystem, progressive pathologies seen in Hunter syndrome. The nervous, cardiovascular, respiratory, and musculoskeletal systems can be involved in individuals with Hunter syndrome. Although the management of some clinical problems associated with the disease may seem routine, the management is typically complex and requires the physician to be aware of the special issues surrounding the patient with Hunter syndrome, and a multidisciplinary approach should be taken. Subspecialties such as otorhinolaryngology, neurosurgery, orthopedics, cardiology, anesthesiology, pulmonology, and neurodevelopment will all have a role in management, as will specialty areas such as physiotherapy, audiology, and others. The important management topics are discussed in this review, and the use of enzyme-replacement therapy with recombinant human iduronate-2-sulfatase as a specific treatment for Hunter syndrome is presented.

Closed Meningo(encephalo)cele: A New Feature in Hunter Syndrome

“…Multiple sulfatase deficiency was excluded by detection of normal activity of other lysosomial sulfatases. The phenotype was judged as "attenuated" and "severe" by pediatricians with expertise in metabolic disorders according to the classification recently published by Muenzer et al 3 Eleven patients presented with the "attenuated" phenotype (mean age 15 years; age range 4.5-32 years), while 22 were classified as the "severe" phenotype (mean age 10.5 years; age range 2.5-19 years).…”

“…In the attenuated form, clinical signs and symptoms occur later, the neurologic deficit is minimal or absent, and patients may survive until late adulthood. 2,3 ERT with recombinant human iduronate-2-sulfatase (idursulfase; Elaprase, Shire Human Genetic Therapies, Cambridge, Massachusetts) has been shown to improve many signs and symptoms of the disease. 1 However, the true impact on the central nervous system and skeletal and skull abnormalities is still debated.…”

Survival in idursulfase‐treated and untreated patients with mucopolysaccharidosis type II: data from the Hunter Outcome Survey (HOS)

“…Somatic involvement in patients without cognitive impairment can range from being severe with early onset to much less severe with later onset (Young et al 1982;Young and Harper 1983;Neufeld and Muenzer 2001;Schwartz et al 2007;Wraith et al 2008b); this group of patients usually exhibits minimal or no neurological involvement. Management of patients with MPS II requires a multidisciplinary approach involving a range of specialties such as cardiology, neurology, psychology, pulmonology and orthopaedics (Wraith et al 2008a;Muenzer et al 2009;Scarpa et al 2011). Disease-specific treatment in the form of enzyme replacement therapy (ERT) with recombinant I2S (idursulfase [Elaprase®]; Shire, Lexington, MA, USA) became available in the USA in 2006 and Europe in 2007, and alleviates many of the somatic signs and symptoms of the disorder (Muenzer et al 2011); before this, symptomatic management was the only possible treatment approach.…”

Enzyme Replacement Therapy in Mucopolysaccharidosis II Patients Under 1 Year of Age

“…Some evidence reported since that time has suggested that earlier treatment before irreversible organ damage occurs may improve clinical outcomes and growth (Muenzer et al 2012;Muenzer et al 2009, SchulzeFrenking et al 2011. A recent 53-week, open-label, safety trial of 0.5 mg/kg weekly idursulfase in children aged 1.4-7.5 years (n ¼ 28) has been completed (Giugliani et al 2013).…”