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HelpTest Code LAB2817 Arylsulfatase A for I Cell
Clinical System Name
.Arylsulfatase A, plasma
Description
Enzyme analysis of total hexosaminidase, % hexosaminidase A, and arylsulfatase A in plasma or serum for diagnosis of I-Cell disease (ML II).
Sample Requirements
Specimen: Whole Blood
Container(s): Dark Green/Sodium Heparin tube, Yellow/ACD A or B, Serum from Gold SST or Red top tubes
Preferred Vol: 2.0 mL
Minimum Vol: 1.0 mL
Processing Instructions
Reject due to:
Spin: Y
Aliquot:Y
Temp:-20 C
Storage location: Biochemical Genetics Box -20 C
Specimen should be spun and aliquoted within 2 hours of collection.
Off-site collection: Transport to Laboratory immediately.
Stability
| Specimen Type | Temperature | Time |
|---|---|---|
| Aliquoted Serum/Plasma | Refrigerated |
7 days |
| Freezer (-20 C)-preferred | 1 month |
Performing Laboratory
Seattle Children's Laboratory
Department
Department: Biochemical Genetics
Phone Number: 206-987-2216
Synonyms
I Cell
Arylsulfatase A, plasma
.Aryl A p
.
Availability
| STAT | Performed | TAT |
|---|---|---|
| N | Weekly | 7 days |
Contact the Biochemical Genetics Lab for requests outside of stated availability (206)987-2216.
Methodology
Method: Enzymatic/Fluorometric; 4-methylumbelliferyl substrate with heat inactivation, and spectrophotometric.
Analytical Volume:
Limitations:
Reference Range
| Specimen Type | Normal Range <1 yr | Normal Range >1 yr |
|
Total hexosaminidase (serum) |
1080-4400 nmol/hr/mL | 600-1844 nmol/hr/mL |
| % Hex A | 42-73% | 42-73% |
| Arylsulfatase A (serum/plasma) | 0 - 100 nmol/hr/mL |
Carrier testing not performed
CPT Codes
83080
Requisition
Biochemical Genetics Requisition
On the requisition include clinical information needed for appropriate interpretation. (Age, gender, drug therapy and family history)
Clinical Utility
Patients with I Cell disease (mucolipidosis type II) have extreme elevation of serum/plasma total Hexosaminidase and Arylsulfatase A.
Carrier testing by enzyme analysis is not available.