Sandhoff Disease (HEXB) Sequencing

Disorder Sandhoff Disease
Gene Name HEXB
Clinical info Sandhoff disease is an autosomal recessive lysosomal storage disorder caused by significantly reduced or absent activities of beta-hexosaminidase A and beta-hexosaminidase B. This deficiency results in accumulation of GM2 ganglioside which leads to the destruction of neurons in the brain and spinal cord. Infants with Sandhoff disease have normal developmental progress until the age of 3-6 months when developmental regression occurs. Features of this progressive condition include an increased startle reflex, a retinal cherry-red spot, seizures, vision and hearing loss, ataxia, and hepatoslenomegaly. Infantile Sandhoff disease typically results in death by age three. In rare cases, Sandhoff disease can occur with later onset, milder symptoms, and slower progression. Higher frequencies of Sandhoff disease have been reported among individuals with backgrounds including Northern Argentina Creole, the Metis population in Saskatchewan, and Lebanese descent.
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.
Associated Tests Enzyme analysis for beta-hexosaminidase is available to rule out Tay-Sachs or Sandhoff disease. Sequencing of HEXB is also included in our NGS Lysosomal Storage Disease Panel.
Specimen Requirements 5 to 10 ml of peripheral blood collected in an EDTA (lavender top) Vacutainer tube is preferred. The minimal blood needed for reliable DNA isolation is 3 ml
Transport The specimen should be kept at room temperature and delivered via overnight shipping. FedEx is preferred. 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.
Turnaround time 21 days
Prenatal testing 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.
CPT Codes

Unknown mutation: 81479

Known mutation: 81403

Deletion/Duplication Analysis: 81479

Cost

$900 for sequencing

$350 for known mutation

$700 for deletion/duplication analysis

Prenatal diagnosis for known mutation is $1000.  Please contact the laboratory for more information.

Contact For further information contact one of our This email address is being protected from spambots. You need JavaScript enabled to view it. at 1-800-473-9411.