Oligosaccharidoses Enzyme Panel

Test Information

This panel of enzymes is intended for patients with a diagnosis or clinical suspicion of an oligosaccharidosis condition and includes quantification of the activity of 6 or 7 enzymes, depending on the sample type. Enzyme analysis and demonstrating deficient activity is considered the gold-standard in diagnosing lysosomal storage disorders.

Turnaround Time

2 weeks

CPT Code(s)

82657 x3

Cost

$600


Enzymes

Alpha-fucosidase
Aspartyglucosaminidase (cannot be measured in fibroblasts)
Beta-galactosidase
Beta-mannosidase
N-acetyl alpha galactosaminidase
Alpha-neuraminidase-sialidase (this enzyme only performed on fibroblasts)

Clinical Information

Lysosomal storage disorders are a broad group of diseases composed of a variety of sub-groups of disorders, such as the mucopolysaccharidoses, the glycoproteinoses, and the sphingolipidoses. A lysosomal storage disease can present in a number of different ways. Infants or children may have growth failure, developmental regression, corneal or lens clouding, hepato- and/or splenomegaly, coarsening facial features and skeletal abnormalities. Some disorders are more likely to have a neurological presentation or present in adults. While a diverse group, different storage diseases may have similar clinical features, thus it may be necessary to measure a number of different enzyme activities prior to finding the one deficient in a particular patient.

Indications

Enzyme testing may be ordered as follow-up to abnormal urine screening or as a first tier testing.

Methodology

Assays for lysosomal enzymes will employ an artificial 4-methylumbelliferyl substrate and activity is measured using a fluorometer. These are quantitated assays and the units will vary among each enzyme.

Specimen Requirements

Enzyme activity can be measured in whole blood, leukocytes, or dried blood spots except for sialidosis which can only be performed in fibroblasts. Please note, if fibroblasts are received then aspartylglucosaminidase cannot be measured. Send 5-7 ml of whole blood in a green top (sodium heparin) tube or skin biopsy in culture media.

Transport Instructions

Whole blood should be sent over overnight at ambient temperature. Do not freeze whole blood. Samples for enzyme analysis must arrive to the lab the next day. For dried blood spots, when sample has dried 3-4 hours, fold cover at score line, over sample, and tuck into flap. Sample should be sent at ambient temperature.

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

Lucy's Story

When our daughter Lucy had a metabolic crisis at 7 days old, we were shocked and devastated to find out that she was born with a rare genetic disorder (MSUD). Her newborn screening results did not make it back in time to prevent the crisis, and no one at our local hospital was familiar with the disease. They did not know how to treat her. Calls were made to Greenwood Genetic Center to confirm her diagnosis and guide her care. Dr. Champaigne and Ami...

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