Fabry Disease : Alpha-galactosidase Enzyme Analysis

Test Information

This biochemical test is a quantitative measurement of alpha-galactosidase enzyme activity and can be used as a 1st tier test for patients with a clinical suspicion of Fabry disease. Demonstration of deficient alpha-galactosidase enzyme activity is considered the gold standard to confirm a diagnosis of Fabry disease.

In addition, this assay can be used to clarify molecular findings in the GLA gene, to follow up abnormal newborn screening results, and to monitor patients undergoing treatment.

Turnaround Time

2 weeks

CPT Code(s)

82657

Cost

$200


Enzymes

Alpha-galactosidase

Disorders

Clinical Information

Fabry disease is a lysosomal storage disorder in which absent or reduced production of alpha-galactosidase A leads to the systemic accumulation of globotriaoslyceramide. Total absence of enzyme production results in the more severe, classic form of Fabry disease, while reduced production of alpha-galactosidase A typically often involves milder symptoms that appear later in life. Episodic pain, angiokeratosis, and hypohydrosis are frequently seen in patients with Fabry disease as well as corneal clouding and hearing loss. Gastrointestinal issues and breathing problems are common, and complications including cardiac abnormalities, kidney disease, and strokes can be life-threatening. Although Fabry disease is an X-linked disorder that primarily affects males, carrier females may become symptomatic. This condition occurs in approximately 1 in 55,000 males, and the development of enzyme replacement therapy has greatly improved the prognosis for many patients.

Indications

This test can be used to confirm a suspected Fabry disease diagnosis.

Methodology

4-methylumbelliferyl substrate.

Specimen Requirements

Enzyme activity can be measured in leukocytes, cultured fibroblasts, or dried blood spots. For leukocytes, please send 5-10 ml of whole blood in a green top (sodium heparin) tube. For dried blood spot collection, a minimum of three circles need to be filled in. Each circle should contain one drop of blood (about 100 microliters). See the link below for additional sample collection and handling instructions.

Transport Instructions

Whole blood samples (for leukocyte analysis) should be shipped at ambient temperature and must arrive at the laboratory within 24 hours of specimen collection.

Cultured fibroblasts should be sent overnight at room temperature.

For a dried blood spot: When the sample has dried 3-4 hours, fold cover at score line, over sample, and tuck into flap. Samples can be mailed 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
Kellie Walden, MS, CGC

Biochemical Testing, Enzyme Analysis, Individual Enzyme Assays
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Meet The Jones Family

The journey to becoming parents did not start as an easy one for my husband and I. We suffered the heartache of miscarriage and the unimaginable pain of burying our first born child. Our son, sweet 1 lb 1.4 ounce, 12 inches long, teeny, tiny little Joseph “Hamilton” Jones was born with spina bifida, hydrocephalus, and a heart defect. It tore our hearts out leaving the hospital without him, knowing our dreams and hope for the future were shattered. ...

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