Preferred test to evaluate symptomatic patients for Tay-Sachs disease or Sandhoff disease. Can identify carriers of Tay-Sachs disease. Can identify carriers of Sandhoff disease. For individuals who are pregnant, use oral contraceptives, have severe liver or autoimmune disease, or have a previous inconclusive HEX A enzyme serum/plasma test, the preferred test is Hexosaminidase A percent and Total Hexosaminidase in Leukocytes (2008125) to avoid false-positive results.
- Patient Preparation
- Yellow (ACD). Also acceptable: Plain red.
- Specimen Preparation
- Do not transfer whole blood to other containers. Transport 3 mL whole blood (Min: 1 mL) or transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.2 mL)
- Storage/Transport Temperature
- Whole blood: Room temperature. Serum: Frozen
- Unacceptable Conditions
- 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.
- Whole blood: Ambient: 3 days; Refrigerated: 3 days; Frozen: Unacceptable
Serum: Ambient: 3 days; Refrigerated: 7 days; Frozen: 1 month
|Available Separately||Components||Reference Interval|
|No||Hexosaminidase A Percent||55-76 percent|
|No||Hexosaminidase Total||Effective August 17, 2015|
600-1050 nmol hydrolyzed/hr/mL
|Component Test Code*||Component Chart Name||LOINC|
|2008123||Hexosaminidase A Percent||12914-8|
|2008124||Hexosaminidase Plasma/Serum Interp|
- Plasma and serum hexosaminidase Hexosaminidase A and Total, plasma or serum