Metachromatic Leukodystrophy : ARSA Sequencing

Test Information

ARSA sequencing is a molecular test used to identify variants in the gene associated with Metachromatic Leukodystrophy.

Turnaround Time

3 weeks

CPT Code(s)

81405

Cost

$1,000

Genes

Clinical Information

Metachromatic leukodystrophy is an autosomal recessive condition caused by a deficiency of arylsulfatase A, an enzyme crucial to the breakdown of sulfatides in the body. The accumulation of sulfatides causes demyelination of nerves. Progressive signs of leukodystrophy include a decline in intellectual abilities and motor skills to the extent that affected individuals lose the ability to walk, speak, see, and hear. This condition can present as late-infantile, juvenile or adult forms, and it is more common in people of Israeli or Navajo descent.

Indications

Metachromatic leukodystrophy should be considered in any individual with progressive neurological dysfunction and MRI evidence of a leukodystrophy. Diagnosis is typically initially made by enzyme testing. Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutations within a family to allow for carrier testing and prenatal diagnosis.

Methodology

Sanger Sequencing

Specimen Requirements

5 to 7 ml of peripheral blood collected in an EDTA (lavender top) tube is the preferred specimen type. The minimal blood needed for reliable DNA isolation is 3 ml. Extracted DNA, dried blood spots, and saliva are also accepted for this test.

Transport Instructions

The specimen should be kept at room temperature and delivered via overnight shipping. If shipment is delayed by one or two days, the specimen should be refrigerated and shipped at room temperature. Do not freeze the specimen. Samples collected on Friday can be safely designated for Monday delivery.

Prenatal Testing Information

Prenatal diagnosis is available if the familial mutations are known. Additional fees for cell culture and maternal cell contamination may apply. Maternal cell contamination studies are required for all prenatal molecular tests. Contact the laboratory prior to sending a prenatal specimen.

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

Molecular Testing, Sanger Sequencing
Meet the Shenal Family

Meet the Shenal Family

Our daughter, Ryleigh, was diagnosed with a rare chromosomal deletion shortly after she was born in 2010. Since we received her diagnosis, the Greenwood Genetic Center has become part of our family. They made certain that we did not feel alone, and they continue to provide ongoing, compassionate care for our child. The impact they have had on our family and others across the globe everyday is immeasurable. We can't imagine walking this journey without their...

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