Recognition and Diagnosis of Mucopolysaccharidosis II (Hunter Syndrome)

Abstract

Mucopolysaccharidosis II, also known as Hunter syndrome, is a rare, X-linked disorder caused by a deficiency of the lysosomal enzyme iduronate-2-sulfatase, which catalyzes a step in the catabolism of glycosaminoglycans. In patients with mucopolysaccharidosis II, glycosaminoglycans accumulate within tissues and organs, contributing to the signs and symptoms of the disease. Mucopolysaccharidosis II affects multiple organs and physiologic systems and has a variable age of onset and variable rate of progression. Common presenting features include excess urinary glycosaminoglycan excretion, facial dysmorphism, organomegaly, joint stiffness and contractures, pulmonary dysfunction, myocardial enlargement and valvular dysfunction, and neurologic involvement. In patients with neurologic involvement, intelligence is impaired, and death usually occurs in the second decade of life, whereas those patients with minimal or no neurologic involvement may survive into adulthood with normal intellectual development. Enzyme replacement therapy has emerged as a new treatment for mucopolysaccharidosis disorders, including Hunter syndrome. The purpose of this report is to provide a concise review of mucopolysaccharidosis II for practitioners with the hope that such information will help identify affected boys earlier in the course of their disease.

Ocular Features of Treatable Lysosomal Storage Disorders – Fabry Disease, Mucopolysaccharidoses I, II and VI and Gaucher Disease

“…Estimates of the prevalence ranging from 0.9:100,000 to 4.5:100,000 have been reported. [40][41][42] …”

Chiari 1 Malformation and Holocord Syringomyelia in Hunter Syndrome

“…Hunter syndrome (Mucopolysaccharidosis type II; MPS-II; OMIM#309900) is a rare X-linked recessive lysosomal storage disorder (1/170,000 live male births) (Martin et al 2008) caused by iduronate-2-sulphatase (IDS; EC3.1.6.13) deficiency. The resulting lysosomal accumulation of upstream metabolites affects a variety of organ systems, including visceral organs, skeleton, connective tissue, and the central nervous system.…”

Obstructive Sleep Apnea Syndrome in Children With Type Ii Mucopolysaccharidosis (Hunter Syndrome)

“…Type II mucopolysaccharidosis (Hunter syndrome) is an extremely rare pathology (X-linked recessive inheritance mode) as frequent as 0.3-0.71 cases per 100,000 on live neonates [1]. Congenital deficit of lysosomal enzyme iduronate-2-sulfatase results in accumulation of glycosaminoglycans (dermatan sulfate, heparan sulfate) with progressive multiorgan lesion.…”