Alpha-mannosidosis Serum Oligosaccharide Analysis

Test Information

Patients with alpha-mannosidosis cannot break down various oligosaccharides that contain a terminal mannose residue, which results in their accumulation in body tissues.  This assay measures five different free oligosaccharides in serum or plasma that accumulate in patients with alpha-mannosidosis and can be used for both the diagnosis and treatment monitoring of patients with this disorder.  GlcNAc(Man)2 is measured quantitatively and GlcNAc(Man)3, GlcNAc(Man)4, GlcNAc(Man)5 and GlcNAc(Man)6 are measured semi-quantitatively.

Turnaround Time

21 days

CPT Code(s)




Clinical Information

Alpha-mannosidosis is caused by a deficiency of the lysosomal enzyme alpha-mannosidase, which is required for the degradation of oligosaccharides containing a terminal mannose residue. The clinical presentation of alpha-mannosidosis varies in severity, but typical features include coarse facial features, intellectual disability, skeletal abnormalities, hearing loss, hepatosplenomegaly and recurrent infections.


Measurement of free oligosaccharides associated with alpha-mannosidosis can be used to aid in the diagnosis of patients with the disorder and to monitor effectiveness of treatment.


Liquid chromatography-tandem mass spectrometry

Specimen Requirements

This test can be performed in either serum (preferred) or plasma isolated from a sodium heparin blood tube. Please send a minimum of 3 mL whole blood in a serum tube (preferred) or a green top (sodium heparin) tube, or spin down the whole blood sample, pull off serum or plasma, and freeze.

Transport Instructions

Whole blood samples should be shipped at ambient temperature and must arrive at the laboratory within 4 days (96 hours) of blood draw. If serum or plasma has been separated and frozen, send frozen via overnight shipping, preferably on dry ice.

Have Questions? Need Support?

Call our laboratory at 1-800-473-9411 or contact one of our Laboratory Genetic Counselors for assistance.
Robin Fletcher, MS, CGC
Falecia Thomas, MS, CGC
Alex Finley, MS, CGC

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