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Genetics Home Reference: your guide to understanding genetic conditions
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IDUA

Reviewed December 2008

What is the official name of the IDUA gene?

The official name of this gene is “iduronidase, alpha-L-.”

IDUA is the gene's official symbol. The IDUA gene is also known by other names, listed below.

What is the normal function of the IDUA gene?

The IDUA gene provides instructions for producing an enzyme called alpha-L-iduronidase, which is essential for the breakdown of large sugar molecules called glycosaminoglycans (GAGs). Through a process called hydrolysis, alpha-L-iduronidase uses water molecules to break down a molecule known as unsulfated alpha-L-iduronic acid, which is present in two GAGs called heparan sulfate and dermatan sulfate. Alpha-L-iduronidase is located in lysosomes, compartments within cells that digest and recycle different types of molecules.

How are changes in the IDUA gene related to health conditions?

mucopolysaccharidosis type I - caused by mutations in the IDUA gene

More than 100 mutations in the IDUA gene have been found to cause mucopolysaccharidosis type I (MPS I). Mutations that change one DNA building block (nucleotide) are the most common. All mutations that cause MPS I reduce or completely eliminate the function of alpha-L-iduronidase. It usually cannot be determined whether a certain mutation will cause severe or attenuated MPS I; however, people who do not produce any alpha-L-iduronidase have the severe form of this disorder.

The lack of alpha-L-iduronidase enzyme activity leads to the accumulation of heparan sulfate and dermatan sulfate within the lysosomes. The buildup of these GAGs increases the size of the lysosomes, which is why many tissues and organs are enlarged in MPS I. Researchers believe that the accumulated GAGs may also interfere with the functions of other proteins inside the lysosomes and disrupt the movement of molecules inside the cell.

Where is the IDUA gene located?

Cytogenetic Location: 4p16.3

Molecular Location on chromosome 4: base pairs 986,996 to 1,004,556

The IDUA gene is located on the short (p) arm of chromosome 4 at position 16.3.

The IDUA gene is located on the short (p) arm of chromosome 4 at position 16.3.

More precisely, the IDUA gene is located from base pair 986,996 to base pair 1,004,556 on chromosome 4.

See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.

Where can I find additional information about IDUA?

You and your healthcare professional may find the following resources about IDUA helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the IDUA gene or gene products?

  • alpha-L-iduronidase
  • IDUA_HUMAN

See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What glossary definitions help with understanding IDUA?

breakdown ; cell ; DNA ; enzyme ; gene ; heparan sulfate ; hydrolysis ; molecule ; mutation ; nucleotide ; sulfate

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).

References

  • Beesley CE, Meaney CA, Greenland G, Adams V, Vellodi A, Young EP, Winchester BG. Mutational analysis of 85 mucopolysaccharidosis type I families: frequency of known mutations, identification of 17 novel mutations and in vitro expression of missense mutations. Hum Genet. 2001 Nov;109(5):503-11. Epub 2001 Oct 19. (http://www.ncbi.nlm.nih.gov/pubmed/11735025?dopt=Abstract)
  • Gene Review: Mucopolysaccharidosis Type I (http://www.ncbi.nlm.nih.gov/books/NBK1162/)
  • Muenzer J. The mucopolysaccharidoses: a heterogeneous group of disorders with variable pediatric presentations. J Pediatr. 2004 May;144(5 Suppl):S27-34. Review. (http://www.ncbi.nlm.nih.gov/pubmed/15126981?dopt=Abstract)
  • NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/3425)
  • Pastores GM, Arn P, Beck M, Clarke JT, Guffon N, Kaplan P, Muenzer J, Norato DY, Shapiro E, Thomas J, Viskochil D, Wraith JE. The MPS I registry: design, methodology, and early findings of a global disease registry for monitoring patients with Mucopolysaccharidosis Type I. Mol Genet Metab. 2007 May;91(1):37-47. Epub 2007 Mar 2. (http://www.ncbi.nlm.nih.gov/pubmed/17336562?dopt=Abstract)
  • Terlato NJ, Cox GF. Can mucopolysaccharidosis type I disease severity be predicted based on a patient's genotype? A comprehensive review of the literature. Genet Med. 2003 Jul-Aug;5(4):286-94. Review. (http://www.ncbi.nlm.nih.gov/pubmed/12865757?dopt=Abstract)
  • Vijay S, Wraith JE. Clinical presentation and follow-up of patients with the attenuated phenotype of mucopolysaccharidosis type I. Acta Paediatr. 2005 Jul;94(7):872-7. (http://www.ncbi.nlm.nih.gov/pubmed/16188808?dopt=Abstract)

 

The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

 
Reviewed: December 2008
Published: July 21, 2014