Mucopolysaccharidosis type 2 (MPS2)


Hunter syndrome (MIM 309900) is an X-linked recessive lysosomal storage disorder. The condition is caused by a deficiency of the enzyme iduronate-2-sulphatase (IDS), which is required for the lysosomal degradation of the glycosaminoglycans, heparan sulphate and dermatan sulphate. Affected males have a characteristic pattern of urine metabolites and a deficiency of the IDS enzyme; biochemical enzyme analysis utilises these features to confirm a clinical diagnosis. Hunter syndrome is clinically heterogeneous, but the predominant clinical features include coarse facial features, stiff joints, hepatosplenomegaly, cardiovascular and respiratory disorders, developmental delay and mental retardation. The IDS gene consists of 9 exons and family specific mutations are found throughout the gene. Homologous recombination between the IDS gene and an adjacent unexpressed IDS pseudogene, located 20kb telomeric of IDS, leads to inversions and deletions, a common inversion accounts for ~10% of Hunter cases.

Also known as

Hunter syndrome, iduronate 2-sulphatase deficiency, IDS deficiency, MPS

Request a test

When requesting this test please use the referral form provided. Please also refer to any additional information provided for this test.

Additional information

Clinically affected patients should have their diagnosis confirmed by biochemical analysis; such patients may then be referred for mutation analysis. If the necessary patient samples are unavailable genetic testing can be undertaken in the mother of the affected child. All confirmed Hunter patients (or their mothers if no sample is available from the affected male) are first tested for the presence of a common inversion, which has been shown to occur in ~10% of Hunter patients. Mutation screening is then undertaken in the remainder of the gene including MLPA analysis to detect large deletions and duplications.

Sending address

Rare & Inherited Disease Laboratory
London North Genomic Laboratory Hub
Great Ormond Street Hospital for Children
Levels 4-6 Barclay House
37 Queen Square

Laboratory service


Sample requirements

1ml EDTA neonates, 5ml EDTA adults

Reference range

Not applicable

Turnaround time

Deletion screen - 20 days; gene screen - 40 days

Disease / group



Upon request

Call in advance?

Prenatals must be arranged in advance, through a Clinical Genetics department if possible.


The Genetics Laboratories provide an extensive range of Cytogenetics and Molecular Genetics diagnostic testing services.

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