Ordering Recommendation

Preferred test to identify carriers of Tay-Sachs disease. Preferred test to identify carriers of Sandhoff disease. Can use to evaluate symptomatic patients for Tay-Sachs disease or Sandhoff disease. Use in pregnant individuals, individuals who use oral contraceptives or hormone replacement therapy, individuals with liver or autoimmune disease, or individuals with a previous inconclusive HEX A enzyme test in plasma/serum. 

Mnemonic
HEXOA LEUK
Methodology

Quantitative Fluorometry

Performed

Mon

Reported

2-9 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Yellow (ACD).

Specimen Preparation

Do not transfer whole blood to other containers. Transport 3 mL whole blood. (Min: 1.0 mL)

Storage/Transport Temperature

Room temperature. Also acceptable: Refrigerated.

Unacceptable Conditions

Whole blood received greater than 3 days from collection. Grossly hemolyzed specimens.

Remarks

Clinical information is needed for appropriate interpretation. Additional required information includes age, gender, diet (e.g.TPN therapy), drug therapy, and family history. Biochemical Genetics Patient History Form is available on the ARUP Web site at http://www.aruplab.com/patienthistory or by contacting ARUP Client Services.

Stability

Ambient: 3 days; Refrigerated: 3 days; Frozen: Unacceptable

Reference Interval

Effective November 18, 2013

Greater than or equal to 63 percent

Interpretive Data

Refer to report.

Compliance Statement B: For laboratory developed tests not using a RUO kit, and for FDA approved, cleared or 510(k) exempt assays with alterations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

Note

This test is used for the diagnosis of Tay-Sachs disease and can also be used to identify carriers for this disorder. Carrier screening is offered to individuals of Ashkenazi Jewish descent because of the high incidence of the disease in this population.

Hotline History
N/A
Components
Component Test Code* Component Chart Name LOINC
2008126 Hexosaminidase A Percent in Leukocytes 23825-3
2008127 Hexosaminidase Total, Leukocytes 50759-0
2008128 Hexosaminidase in Leukocytes Interp 21328-0
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • HEXA enzyme testing
  • Hexosaminidase A and Total, leukocytes
Hexosaminidase A Percent and Total Hexosaminidase in Leukocytes