Mucopolysaccharidosis VII, Sly Syndrome : GUSB Sequencing

GUSB sequencing is a molecular test used to identify variants in the gene associated with Mucopolysaccharidosis VII (MPS VII), Sly Syndrome.

Turnaround Time

3 weeks

CPT Code(s)

81479

Cost

$1,000

Genes

Sly syndrome, or mucopolysaccharidosis type VII, is a lysosomal storage disorder resulting from deficient enzyme activity of beta-glucuronidase. This autosomal recessive disorder has a highly variable phenotype. The most severe form presents prenatally as hydrops fetalis. Patients with a less severe phenotype present with hepatomegaly, skeleltal anomalies and coarse facies. The degree of cognitive impairment varies with the mildest cases surviving into adulthood.

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.

Sanger Sequencing

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.

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 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.