Glycogen Storage Disease Type II, Pompe disease : GAA Sequencing

Test Information

GAA sequencing is a molecular test used to identify variants in the gene associated with Glycogen Storage Disease Type II, Pompe disease.

Turnaround Time

3 weeks

CPT Code(s)

81406

Cost

$1,000

Genes

Clinical Information

Pompe disease is caused by a deficiency of the enzyme alpha-glucosidase (GAA), an enzyme that at normal levels will breakdown glycogen in the body. Infantile-onset Pompe disease is characterized by hypotonia, generalized muscle weakness and hypertrophic cardiomyopathy. Death generally occurs within the first year of life due to cardiac and respiratory failure. The later-onset form shows greater variability with a slowly progressive muscle weakness and respiratory insufficiency. The degree of enzyme deficiency is generally related to the severity and age of onset.

Indications

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, Newborn Screening Follow-Up, Sanger Sequencing
Meet the Shorter Boys

Meet the Shorter Boys

Unexpected. If there is a term that sums up life it could very well be: unexpected. Life is full of unexpected moments. Some of these moments can be full of unexpected blessings while others may be full of unexpected obstacles. However, sometimes the unexpected can be both an obstacle and blessing at the same time; you just need someone to help you see both sides. The Greenwood Genetic Center is a place that helps shed some light on the...

In The News