Hexosaminidase A

GM2 gangliosidosis (Tay Sachs / B1 variant)

Chemical Pathology - Enzyme

For the diagnosis of Tay Sachs disease and variants (diseases resulting from mutations in the HEXB gene associated with a deficiency of HexA but unaffected HexB). The two major isoenzymes of lysosomal β-N-acetyl hexosaminidase – namely hexosaminidase A (HexA) and hexosaminidase B (HexB) – are assayed in plasma, leucocytes, cultured cells and tissues. HexA is found to be deficient in cases of Tay Sachs disease

1. 5 - 10 mL lithium heparin whole blood or

2. Cultured fibroblasts or

3. Chorionic villi or

4. Cultured chorionic villi or

5. Cultured amniotic cells

1. Send whole blood at ambient room temperature to reach the lab ideally within 24 hours of collection

2. Send flask completely filled with medium at room temperature a in well insulated container. To reach lab ideally within 24 hours

3. Contact the Enzyme Laboratory PRIOR to sampling and shipping

4. Contact the Enzyme Laboratory PRIOR to sampling and shipping

5. Contact the Enzyme Laboratory PRIOR to sampling and shipping

1. 4 to 6 weeks

2. 4 to 6 weeks

3. As soon as practically possible

4. As soon as practically possible

5. As soon as practically possible

Tay-Sachs disease, B variant GM2 gangliosidosis, GM2 gangliosidosis type 1, HexA deficiency, Hexosaminidase A deficiency

1. Yes

2. Yes

3. Yes

4. Yes

5. Yes