Iduronate-2-Sulfatase, Leukocytes
Use
This test supports the biochemical diagnosis of mucopolysaccharidosis II (MPS II; Hunter syndrome) in whole blood specimens. MPS II is an X-linked lysosomal disorder caused by the deficiency of iduronate sufatase enzyme due to variants in the IDS gene. The clinical features and severity of symptoms vary widely, ranging from severe infantile onset disease to milder forms with later onset. Symptoms include coarse facies, short stature, enlarged organs, and neurologic involvement. Early diagnosis and treatment are desirable due to availability of therapies such as stem cell transplantation and enzyme replacement, which improve outcomes.
Special Instructions
Not provided.
Limitations
This test is not useful for carrier detection for MPS II. Pseudodeficiency alleles can show reduced enzyme activity. Enzyme levels may be normal in individuals receiving replacement therapy or transplants. Iduronate-2-sulfatase deficiency also occurs in multiple sulfatase deficiency, making enzyme testing unreliable for carrier detection. Additional biochemical or molecular testing is needed to confirm diagnosis.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
IDS
Gene
LOINC Codes
- 24089-5 - Iduronate2Sulfatas WBC-cCnt
- 24089-5 - Iduronate2Sulfatas WBC-cCnt
- 42349-1
- 59462-2 - Clinical biochemist review
- 18771-6 - Provider signing name
Result Turnaround Time
8-15 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
6 mL
Minimum Volume
5 mL
Container
Yellow top (ACD solution B) preferred; ACD solution A or EDTA acceptable
Collection Instructions
Send whole blood specimen in original tube. Do not aliquot.
Storage Instructions
Refrigerated preferred; Ambient acceptable for 6 days.
Causes for Rejection
Gross hemolysis
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 6 days |
| Refrigerated | 6 days |