Hexosaminidase A and Total Hexosaminidase, Leukocytes

Useful For:

• Carrier detection and diagnosis of Tay-Sachs disease
• Carrier detection and diagnosis of Sandhoff disease

Results for hexosaminidase A and total enzyme analysis are reported with recommendations for additional testing when appropriate. All follow-up testing must be ordered separately on new specimens. This test is appropriate for males and pregnant or nonpregnant females.

• Mayo Tay Sachs Disease Carrier Testing Protocol

Hexosaminidase Total:

Hexosaminidase Percent A:

Cautions:

• A small percentage (<0.5%) of carriers may exhibit normal hexosaminidase A activity and will not be detected by this method. (1)
• GM2 activator deficiency (GM2-gangliosidosis, AB variant) is a rare disorder with clinical features similar to Tay-Sachs and Sandhoff diseases; however, levels of both hexosaminidase A and B are normal. GM2 activator deficiency cannot be identified through testing offered at Mayo Clinic Laboratories.

10 mL blood in YELLOW TOP (ACD) tube

• ACD Solution B preferred; ACD Solution A accepted.

Outside Laboratories: Refrigerate whole blood in original collection container and expedite transport to the lab. Specimen must be received by Mayo within 6 days of collection.

Stability: Refrigerated (Preferred): 6 days; Ambient: 6 days; Frozen: Unacceptable.

Reject Due To: Gross hemolysis.

Refrigerate whole blood in original collection container.

Login: GSEND1-;REFRIG

• RSNDT1: MAYO
• RSTYP1: WB
• RTSRQ1: ;Hexosaminidase A and Total Hexosaminidase, Leukocytes (Mayo Test NAGW)

Sendouts:

• Order Mayo Test: NAGW.
• Same day shipment is preferred. For optimal isolation of leukocytes, the specimen must arrive at Mayo within 6 days of collection to be stabilized.

Stability: Refrigerated (Preferred): 6 days; Ambient: 6 days; Frozen: Unacceptable.

Reject Due To: Gross hemolysis.