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Test ID: NAGR    
Hexosaminidase A and Total, Leukocytes/Molecular Reflex

NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.


Useful For Suggests clinical disorders or settings where the test may be helpful

Recommended test for carrier detection and diagnosis of Tay-Sachs disease


Carrier detection and diagnosis of Sandhoff disease (testing option-not the recommended test)

Genetics Test Information Provides information that may help with selection of the correct test or proper submission of the test request

This is the most comprehensive assay for diagnosis and carrier detection of Tay-Sachs disease. Hexosaminidase A analysis is performed initially to assess enzyme level. Samples identified within the affected, carrier, or ambiguous enzyme ranges are reflexed to the Molecular Genetics Laboratory for mutation analysis TSD / Tay-Sachs Disease, Mutation Analysis, HEXA).

Reflex Tests Lists test(s) that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial test(s)

Test IDReporting NameAvailable SeparatelyAlways Performed
TSDTay-Sachs, Mutation AnalysisYesNo

Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.

If hexosaminidase A is <63%, then TSD / Tay-Sachs Disease, Mutation Analysis, HEXA will be added and performed at an additional charge.


See Tay-Sachs Disease Carrier Testing Protocol in Special Instructions.

Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test

Method Name A short description of the method used to perform the test

Heat Inactivation, Fluorometric, Semiautomated

Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name

Hexosaminidase A and Tot, WBC/Mole

Aliases Lists additional common names for a test, as an aid in searching

GM2 Gangliosidosis
Hex A Deficiency
Hexosaminidase A
Sandhoff Carrier Screening
Sandhoff Disease
Sandhoff Disease Carrier Screening
Tay Sachs Carrier Screening
Tay Sachs Disease
Tay Sachs Disease Carrier Screening
Tay Sachs Enzyme Testing with Molecular Reflex
Tay-Sachs Carrier Screening
Tay-Sachs Disease (TSD)
Tay-Sachs Disease Carrier Screening
Tay-Sachs Enzyme Testing With Molecular Reflex
TSD (Tay-Sachs Disease)