Hexosaminidase A and Total Hexosaminidase, Leukocytes
Use
This test is useful for carrier detection and diagnosis of Tay-Sachs and Sandhoff diseases, which are lysosomal storage disorders caused by deficiencies in enzymes hexosaminidase A and B. These conditions lead to the accumulation of GM2 ganglioside and related glycolipids, causing clinical symptoms such as motor deterioration, vision loss, seizures, and the characteristic cherry-red spot in the retina. The test is appropriate for both males and females, including pregnant women, to aid in the diagnostic process or determine carrier status.
Special Instructions
Specimen should be shipped refrigerated and must arrive within 6 days of collection to ensure optimal isolation of leukocytes. Specimen collection is recommended Monday through Thursday and not on the day before a holiday to minimize the time to analysis and prevent degradation of sample quality.
Limitations
A small percentage of carriers may exhibit normal hexosaminidase A activity, leading to false negatives in carrier screening. GM2 activator deficiency, which has similar clinical features, is not detected with this assay. Further molecular genetic testing is recommended to confirm carrier status for pseudodeficiency alleles and facilitate prenatal diagnosis in at-risk individuals.
New York Approved
Methodology
Other (Fluorometric)
Biomarkers
LOINC Codes
- 87544-3
- 24075-4
- 23825-3
- 59462-2
- 18771-6
Result Turnaround Time
2-8 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
6 mL
Minimum Volume
5 mL
Container
Yellow top (ACD solution B) or Yellow top (ACD solution A)
Collection Instructions
Send whole blood specimen in original tube. Do not aliquot.
Causes for Rejection
Gross hemolysis
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 6 days |
| Refrigerated | 6 days |