Hexosaminidase (Tay-Sachs), Leukocytes

Tay-Sachs, GM2 Gangliosidosis, Hexosaminidase A, Total Hexosaminidase, Sandoff's disease, Autyl Glucosaminidase , MAYO: NAGW, Antrim #82350, EPIC: LAB6053, SOFT: XHEXL


  • For Hexosaminidase (Tay-Sachs) testing, this is the preferred test for pregnant females.
  • Due to stability concerns, specimens must be received by the referral laboratory within 96 hours of collection. Specimens may only be collected Monday - Thursday.

Specimen Collection Criteria

Collect: One Yellow-top ACD tube.

Send specimen for processing immediately after collection.

Physician Office/Drawsite Specimen Preparation

Arrange for transportation to the Laboratory prior to specimen collection. Do not centrifuge or freeze. Refrigerate (2-8°C or 36-46°F) specimen in the original collection tube prior to transport.

Preparation for Courier Transport

Transport: 6.0 mL whole blood in original collection tube, refrigerated (2-8°C or 36-46°F). (Min: 5.0 mL)

Rejection Criteria

  • Centrifuged specimens.
  • Grossly hemolyzed specimens.
  • Specimens not collected and processed as indicated.


Monday, Thursday, and alternating Fridays.
Results available in 5-9 days.

Reference Range

By report.

Test Methodology

Heat Inactivation, Fluorometric, Semiautomated.


The key factor for determining carrier status is percent A.

  • Less than 58% A is a carrier.
  • Less than 20% A is Tay-Sachs disease.
  • Greater than or equal to 76% is a Sandhoff carrier.
  • 63-75% A is normal.
  • 58-62% A is ambiguous.
  • Total activity near zero is found in Sandhoff disease.

Clinical Utility

This assay aids in the diagnosis of Tay-Sachs disease, carriers of Tay-Sachs, Sandhoff's disease, and carriers of Sandhoff's. This is the preferred test for pregnant females.

CPT Code


Test Codes

MAYO: NAGW, Antrim #82350, EPIC: LAB6053, SOFT: XHEXL

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