Lysosomal Free Sialic Acid Storage Disorders

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It is possible that the main title of the report Lysosomal Free Sialic Acid Storage Disorders is not the name you expected.

Disorder Subdivisions

  • None

General Discussion

Free sialic acid storage disorders are a group of related disorders characterized by the abnormal accumulation of sialic acid in various cells and tissues of the body. These disorders are generally broken down into three subtypes: infantile free sialic acid storage disease (ISSD), the most severe form; Salla disease, the mildest form; and intermediate Salla disease which is less severe than ISSD, but more serious than Salla disease. The specific symptoms associated with these disorders can vary greatly. All the disorders are characterized by some degree of degeneration of nerve cells (neurodegeneration) and cognitive impairment. Free sialic acid storage disorders occur because of mutations of the SLC17A5 gene and are inherited in an autosomal recessive fashion.

Free sialic acid storage disorders belong to a larger group of disorders known as lysosomal storage disorders. Lysosomes are membrane-bound compartments within cells. They contain enzymes that break down large molecules such as proteins, carbohydrates and fats into their building blocks. Low levels or inactivity of a transport protein known as sialin leads to the abnormal accumulation (storage) of sialic acid in the tissues of affected individuals. Sialin normally helps transport sialic acid out of lysosomes.


CLIMB (Children Living with Inherited Metabolic Diseases)
Climb Building
176 Nantwich Road
Crewe, CW2 6BG
United Kingdom
Tel: 4408452412173
Fax: 4408452412174

Vaincre Les Maladies Lysosomales
2 Ter Avenue
Massy, 91300
Tel: 0169754030
Fax: 0160111583

National Tay-Sachs and Allied Diseases Association, Inc.
2001 Beacon Street
Brookline, MA 02146-4227
Tel: (617)277-4463
Fax: (617)277-0134
Tel: (800)906-8723

March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
Tel: (914)997-4488
Fax: (914)997-4763

The Arc
1825 K Street NW, Suite 1200
Washington, DC 20006
Tel: (202)534-3700
Fax: (202)534-3731
Tel: (800)433-5255
TDD: (817)277-0553

NIH/National Institute of Neurological Disorders and Stroke
P.O. Box 5801
Bethesda, MD 20824
Tel: (301)496-5751
Fax: (301)402-2186
Tel: (800)352-9424
TDD: (301)468-5981

GOLD, Global Organisation For Lysosomal Diseases
3 Albion Rd
Chalfont St Giles
Buckinghamshire, HP8 4EW
United Kingdom
Tel: 441494870708

Hide & Seek Foundation for Lysosomal Disease Research
6475 East Pacific Coast Highway Suite 466
Long Beach, CA 90803
Tel: (877)621-1122
Fax: (866)215-8850

Myelin Disorders Bioregistry Project (MDBP)
Childrens National Medical Center, c/o Dr. Adeline Vanderver
111 Michigan Ave., NW
Washington, DC 20010
Tel: (202)476-6230
Fax: (202)476-5226

For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders (NORD). A copy of the complete report can be downloaded free from the NORD website for registered users. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational therapies (if available), and references from medical literature. For a full-text version of this topic, go to and click on Rare Disease Database under "Rare Disease Information".

The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.

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Last Updated:  3/13/2013
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