A RARE CASE OF HUNTER SYNDROME – CASE REPORT

Lorena Elena Melit,Maria Oana Marginean,Carmen Duicu,Cristina Campean,Oana Marginean

doi:10.37897/rjp.2015.1.8

Abstract

Mucopolysaccharidoses (MPSs) are a group of rare genetic disorders within the larger family of lysosomal diseases. MPSs disorders are caused by a deficiency in the activity of a specific lysosomal enzyme required for the degradation of glycosaminoglycans (GAGs). MPS type II, also called Hunter syndrome consists in a deficiency of an enzyme, iduronate-2-sulphatase. We present a rare case of Hunter syndrome with atypical presentation. It is a case about a boy of 2.7 year old who presented to the Paediatric Clinic with symptoms of a respiratory tract infection and a history of frequent ear infections and respiratory tract infections. His clinical examination showed the following abnormalities: high stature, moderately overweight, facial dysmorphism (coarse facial features, prominent forehead, a depressed nasal bridge), small stubby fingers with flexion of distal interphalangeal joints, joint stiffness, protruding abdomen with umbilical hernia, hepatomegaly and splenomegaly, and also mild mental retardation. The clinical aspect was suggestive for MPS type I, II or VII. Dosage of enzymes with role in mucopolysaccharide lysosomal metabolism revealed low levels of iduronate-2-sulphatase, changes that bent for MPS type II. Enzymatic diagnosis was confirmed by molecular DNA analysis that showed a hemizygote mutation of iduronate2-sulphatase gene in intron 3 (c.419-2A > G). Enzyme replacement therapy with recombinant human iduronate2-sulfatase (Elaprase®) was started. The evolution of the case after almost two years of treatment with Elaprase is favorably, without loss of neurological acquisitions.

Highlights

Mucopolysaccharidosis type II or Hunter syndrome is a lysosomal storage, which results from the deficiency of the enzyme called iduronate2-sulphatase (IDS)
This enzyme being responsible for the degradation of heparan and dermatan sulphate, its absence will lead in the case of afflicted patients to the accumulation of these substances in different tissues, determining in this way the clinical picture of this disease [1,2]
Throughout the presentation of this case, we want to underline the atypical clinical picture of this patient, with mild mental retardation without corneal impairment, respectively the diagnosis and treatment problems raised by this case

Summary

Introduction

Mucopolysaccharidosis type II or Hunter syndrome is a lysosomal storage, which results from the deficiency of the enzyme called iduronate2-sulphatase (IDS). This enzyme being responsible for the degradation of heparan and dermatan sulphate, its absence will lead in the case of afflicted patients to the accumulation of these substances in different tissues, determining in this way the clinical picture of this disease [1,2].

Results

Conclusion