Alpha-Iduronidase Enzyme Activity in Leukocytes
Also known as: A-I LEUK
Use
This test is used to diagnose patients for mucopolysaccharidosis type I (MPS I), also known as Hurler, Scheie, and Hurler-Scheie syndromes. It measures the activity of the enzyme alpha-L-iduronidase in leukocytes, which is deficient in individuals with MPS I. The test aids in identifying affected individuals, although it cannot predict disease severity. Molecular testing of the IDUA gene should be considered to exclude MPS I or pseudodeficiency.
Special Instructions
This test is New York state approved and utilizes the Laboratory Developed Test (LDT) compliance category. Additional information required includes the clinical indication for testing. A Mucopolysaccharides (MPS) Testing Patient History Form is recommended for submission with the order.
Limitations
This test cannot predict disease severity and does not evaluate enzyme activities deficient in other mucopolysaccharidoses. It does not exclude other lysosomal storage disorders. Normal enzyme activity may also be observed in treated individuals who are receiving enzyme replacement therapy or have undergone bone marrow transplant. Consideration should be given to molecular testing of the IDUA gene to exclude MPS I or pseudodeficiency. Pseudodeficiency has been shown due to specific variants affecting the exogenous substrate used by this assay, but not endogenous substrates.
New York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 24057-2
- 48767-8
Result Turnaround Time
3-10 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
1 mL
Container
Yellow (ACD Solution B), lavender (K2EDTA), or lavender (K3EDTA).
Causes for Rejection
Grossly hemolyzed or heparinized specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 3 days |
| Refrigerated | 3 days |
| Frozen | Unacceptable |