Mannosidosis Health Article

Diagnosis

All types of mannosidosis are tested in the same way. In an infant, child, or adult, doctors can check the patient's urine for abnormal types of sugar. They may also test the patient's blood cells to learn if the enzyme is present.

If doctors suspect that a pregnant woman may be carrying a child with mannosidosis, they can test cells in the fluid surrounding the baby for enzyme activity.

Treatment and management

There is no known treatment for mannosidosis. The symptoms—mental retardation and skeletal abnormalities—are managed by supportive care, depending on the severity. Patients with adult alpha-mannosidosis and beta-mannosidosis may show mild mental retardation or behavior problems (such as depression or aggression) and may be mainstreamed into society. Others may require institutionalization. Skeletal abnormalities may require surgery to correct them, and recurring infections are treated with antibiotics.

Research with animals suggests that mannosidosis can be treated by placing healthy cells without defective genes into the animals' bones (bone marrow transplant). Other researchers have successfully treated mannosidosis in animals by inserting healthy genes into the unborn offspring of a pregnant animal. These treatments have not been proven on humans, however.

Prognosis

The future for patients with mannosidosis varies with the form of their disorder. For infants with alpha-mannosidosis, death is expected between ages three and 12 years. For infants with beta-mannosidosis, death will come earlier, by the time they are 15 months old.

Patients with mild forms of alpha- and beta-mannosidosis often survive into adulthood, but their lives are complicated by mental retardation and physical deterioration. They will generally die in their early or middle years, depending on the severity of their disorder.

BOOKS

Thomas, George. "Disorders of Glycoprotein Degradation: Alpha-Mannosidosis, Beta-Mannosidosis, Fucosidosis, and Sialidosis." In The Metabolic and Molecular Bases of Inherited Disease. Scriver, Charles R., et al., ed. Vol. II, 8th ed. New York: McGraw-Hill, 2001.

PERIODICALS

Alkhayat, Aisha H., et al. "Human Beta-Mannosidase cDNA Characterization and First Identification of a Mutation Associated with Human Beta-Mannosidosis." Human Molecular Genetics 7, no. 1 (1998): 75–83.

Berg, Thomas, et al. "Spectrum of Mutations in Alpha-Mannosidosis." American Journal of Human Genetics 64 (1999): 77–88.

Michalski, Jean-Claude, and Andre Klein. "Glycoprotein Lysosomal Storage Disorders: Alpha- and Beta-Mannosidosis, Glucosidosis, and Alpha-N-Acetylgalactosaminidase Deficiency." Biochimica et Biophysica Acta: Molecular Basis of Disease 1455, no. 2–3 (October 8, 1999): 69–84.

ORGANIZATIONS

Arc (a National Organization on Mental Retardation). 1010 Wayne Ave., Suite 650, Silver Spring, MD 20910. (800) 433-5255. <http://www.thearclink.org>.

Children Living with Inherited Metabolic Diseases. The Quadrangle, Crewe Hall, Weston Rd., Crewe, Cheshire, CW1-6UR. UK 127 025 0221. Fax: 0870-7700-327. <http://www.climb.org.uk>.

International Society for Mannosidosis and Related Diseases. 3210 Batavia Ave., Baltimore, MD 21214. (410) 254-4903. <http://www.mannosidosis.org>.

National MPS Society. 102 Aspen Dr., Downingtown, PA 19335. (610) 942-0100. Fax: (610) 942-7188. info @mpssociety.org. <http://www.mpssociety.org>.

WEBSITES

Web Site for Rare Genetic Diseases in Children: Lysosomal Storage Diseases. <http://mcrcr2.med.nyu.edu/murphp01/lysosome/lysosome.htm>.

Linnea E. Wahl, MS