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Diagnostic Services

Genetics Lab


Sandhoff Disease Enzyme Assay

Sandhoff disease is an autosomal recessive lysosomal storage disorder caused by mutations in the HEXB gene which disrupts the activity of beta-hexosaminidase A and beta-hexosaminidase B, preventing the breakdown of GM2 ganglioside. A buildup of GM2 ganglioside in the central nervous system leads to the progressive destruction of nerve cells. As the disease progresses, children with Sandhoff disease develop seizures, vision and hearing loss, cherry red spot of the macula, mental retardation, and paralysis. They can also have organomegaly and skeletal abnormalities.

Test Name: GM2 Gangliosidosis (Tay Sachs) (Hexosaminidase, %A) serum
Test Code:
Test Description:
Spectrophotometric assay of beta-hexosaminidase A & B plus the percentage activity of beta-hexosaminidase A in serum.
Hexosamindase B; Sandhoff;
This is a diagnostic test for individuals suspected of being affected with Sandhoff disease. This tests is not appropriate for carrier testing or prenatal testing.
Related Tests: Oligosaccharides, Urine  
This test is used to screen patients with neurodegenerative symptoms suggestive of a glycoprotein storage disorder.

Clinical Links: NLM Genetics Home Reference - Sandhoff Disease
Turnaround Time:
7 days
Reference Range:
Interpretive report is provided
Consent Form:
Sample Requirements: Type
Whole blood 2 ml, red or gold top tube
Fibroblasts: 2 T-25 flasks
Skin biopsy: 2-4mm skin punch biopsy

Blood: spin and freeze serum
Fibroblasts/skin biopsy: Place in appropriate media

Ship serum frozen, overnight. Blood sample MUST be received within 24 hours of collection.
Ship fibroblasts/biopsy in appropriate cell culture/transport media
Samples Received:
Mon- Fri 8am - 5pm PST For Thursday shipping please arrange for AM courier delivery.
Special Considerations:
If fresh skin biopsy is submitted, Fibroblast Culture (CH-SKIN) must be ordered separately. Please call to discuss
Please e-mail Client Services or call at 206-987-2617 with any billing questions
CPT Code:
Please e-mail Client Services or call at 206-987-2617 with any billing questions