Mucopolysaccharidosis IIIA (MPS IIIA), Sanfilippo syndrome A : SGSH Sequencing

Test Information

SGSH sequencing is a molecular test used to identify variants in the gene associated with Mucopolysaccharidosis IIIA (MPS IIIA), Sanfilippo syndrome A.

Turnaround Time

3 weeks

CPT Code(s)

81479

Cost

$1,000

Genes

Clinical Information

Sanfilippo syndrome is caused by a defect in one of four enzymes required for the modification and removal of glucosamine residues from heparan sulfate. A defect in one of these four enzymes (types A-D) results in the accumulation of heparan sulfate in the patient�s cells and organs which overtime leads to the clinical phenotype. Patients with Sanfilippo syndrome experience delayed development with a progressively deteriorating mental status. Behavior and sleep problems are common as well as coarse facial features and stiff joints. The four types of Sanfilippo syndrome (A-D) are clinically indistinguishable, thus enzyme testing is recommended as an initial diagnostic test.

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

Detection

Sequencing of the gene will detect mutations in >90% of individuals with enzymatically confirmed Sanfilippo syndrome, Type A.

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

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