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HelpTest Code LAB3066 Galactose-6-sulfatase
Clinical System Name
galactose-6-sulfatase
Synonyms
Morquio enzyme
Morquio A
MPS IVa
Morquio B
Beta-galactosidase
Sample Requirements
Specimen: Whole Blood
Container(s): Yellow/ACD A or B, Dark Green/Sodium Heparin Tube
Preferred Vol:10.0 mL
Minimum Vol: 6.0 mL
Note: Also acceptable: cultured cells from skin fibroblasts (2 confluent T-25 flasks)
Do NOT use gel separator tubes.
Processing Instructions
Reject due to:
Spin: N
Aliquot:N
Temp:RT
Storage location: Biochemical Genetics Box- RT
Weekend Processing: Contact Chem West (x72565) on dayshift. If Chemistry team is unavailable, sample should be stored in RT Biochemical Genetics box.
Off-site collection: Do not spin! Keep at room temperature. Transport M-Th at room temperature via overnight shipping.
Stability
| Specimen Type | Temperature | Time |
|---|---|---|
| Room temp |
≤ 24 hrs |
|
| Refrigerated | < 24 hrs |
Samples received > 24 hr after blood collection will still be processsed and test performed if possible.
Availability
| STAT | Performed | TAT |
|---|---|---|
| N | Weekly | 7-10 days |
Contact the Biochemical Genetics Lab for requests outside of stated availability (206)987-2216.
Performing Laboratory
Seattle Children's Laboratory
Department
Department: Biochemical Genetics
Phone Number: 206-987-2216
CPT Codes
82657
Methodology
Method: 4 Mu Fluorometric assay
Analytical Volume:
Limitations:
Reference Range
| Specimen Type | Normal Range (nmol/17hr/mg protein) |
|
WBC |
25-200 |
| FB (Fibroblast) | 95-360 |
Description
Fluorometric enzyme test for N-galactose-6-sulfatase for diagnosis of Morquio A (MPS IV a). Beta-galactosidase is included in the test as a control, and can be used for the diagnosis of Morquio B (MPS IV b).
Requisition
Biochemical Genetics Requisition
On the requisition include clinical information needed for appropriate interpretation. (Age, gender, drug therapy and family history)
Clinical Utility
Enzyme testing for Morquio would be indicated in a child with skeletal findings suggestive of Morquio disease with or without an elevated urine mucopolysaccharide (MPS). Urine MPS is typically elevated in all individuals with MPS disorders, including MPS IV, however, the sensitivity of the MPS assay for keratan sulfate (excreted in MPS IV), is lower than for other glycosaminoglycans.
This test is not appropriate for determining carrier status or for prenatal diagnosis.