Table 1.

Molecular Genetic Testing Used in MPS II (Hunter Syndrome)

Gene 1MethodProportion of Pathogenic Variants 2 Identified by Method
IDS Sequence analysis 382% 4, 5
Gene-targeted deletion/duplication analysis 69%
Complex rearrangements 79%
1.

See Table A. Genes and Databases for chromosome locus and protein.

2.

See Molecular Genetics for information on variants detected in this gene.

3.

Sequence analysis detects variants that are benign, likely benign, of uncertain significance, likely pathogenic, or pathogenic. Variants may include missense, nonsense, and splice site variants and small intragenic deletions/insertions; typically, exon or whole-gene deletions/duplications are not detected. For issues to consider in interpretation of sequence analysis results, click here.

4.

Single-nucleotide changes and splicing variants account for 65% of all pathogenic variants; small (i.e., intra-exon) deletions and insertions account for 17% of all pathogenic variants [Froissart et al 2007].

5.

Sequence analysis may not detect complex rearrangements in males or females that result from a common pathogenic inversion between IDS and IDSP1.

6.

Gene-targeted deletion/duplication analysis detects intragenic deletions or duplications. Methods used may include a range of techniques such as quantitative PCR, long-range PCR, multiplex ligation-dependent probe amplification (MLPA), and a gene-targeted microarray designed to detect single-exon deletions or duplications.

7.

Complex rearrangements result from recombination with the IDSP1 pseudogene or from other types of processes. Testing may require multiple molecular methods (e.g., sequencing, SNP analysis, gene-targeted deletion/duplication analysis, chromosomal microarray) to confirm and map rearrangement breakpoints [Lualdi et al 2005, Froissart et al 2007, Oshima et al 2011].

From: Mucopolysaccharidosis Type II

Cover of GeneReviews®
GeneReviews® [Internet].
Adam MP, Feldman J, Mirzaa GM, et al., editors.
Seattle (WA): University of Washington, Seattle; 1993-2024.
Copyright © 1993-2024, University of Washington, Seattle. GeneReviews is a registered trademark of the University of Washington, Seattle. All rights reserved.

GeneReviews® chapters are owned by the University of Washington. Permission is hereby granted to reproduce, distribute, and translate copies of content materials for noncommercial research purposes only, provided that (i) credit for source (http://www.genereviews.org/) and copyright (© 1993-2024 University of Washington) are included with each copy; (ii) a link to the original material is provided whenever the material is published elsewhere on the Web; and (iii) reproducers, distributors, and/or translators comply with the GeneReviews® Copyright Notice and Usage Disclaimer. No further modifications are allowed. For clarity, excerpts of GeneReviews chapters for use in lab reports and clinic notes are a permitted use.

For more information, see the GeneReviews® Copyright Notice and Usage Disclaimer.

For questions regarding permissions or whether a specified use is allowed, contact: ude.wu@tssamda.

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.