Test Code I2SB Iduronate-2-Sulfatase, Blood Spot
Necessary Information
1. Patient's age is required.
2. Reason for testing is required.
Specimen Required
Submit only 1 of the following specimen types:
Preferred:
Specimen Type: Blood spot
Supplies: Card-Blood Spot Collection (Filter Paper) (T493)
Container/Tube:
Preferred: Blood spot collection card
Acceptable: Whatman Protein Saver 903 Paper, PerkinElmer 226 filter paper, Munktell filter paper, or blood collected in tubes containing ACD or EDTA and dried on filter paper.
Specimen Volume: 2 Blood spots
Collection Instructions:
1. An alternative blood collection option for a patient older than 1 year is a fingerstick. For detailed instructions, see How to Collect Dried Blood Spot Samples.
2. At least 2 spots should be complete (ie, unpunched).
3. Let blood dry on the filter paper at room temperature in a horizontal position for 3 hours.
4. Do not expose specimen to heat or direct sunlight.
5. Do not stack wet specimens.
6. Keep specimen dry.
Specimen Stability Information: Refrigerated (preferred) 60 days/Ambient 7 days/Frozen 60 days
Additional Information:
1. For collection instructions, see Blood Spot Collection Instructions
2. For collection instructions in Spanish, see Blood Spot Collection Card-Spanish Instructions (T777)
3. For collection instructions in Chinese, see Blood Spot Collection Card-Chinese Instructions (T800)
Acceptable:
Specimen Type: Whole Blood
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD)
Specimen Volume: 2 mL
Collection Instructions: Send whole blood specimen in original tube. Do not aliquot.
Specimen Stability Information: Refrigerate (preferred) 7 days/Ambient 48 hours
Forms
1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available:
-Informed Consent for Genetic Testing (T576)
-Informed Consent for Genetic Testing-Spanish (T826)
2. Biochemical Genetics Patient Information (T602)
3. If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.
Useful For
Supporting the biochemical diagnosis of mucopolysaccharidosis II (MPS II; Hunter syndrome)
This test is not useful for determining carrier status for MPS II.
Reflex Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
MPSBS | Mucopolysaccharidosis, BS | Yes | No |
Testing Algorithm
If result interpretation is normal, testing is complete.
If result interpretation indicates mucopolysaccharidosis type II, quantitation of heparan sulfate, dermatan sulfate and keratan sulfate may be performed at an additional charge.
For more information see Newborn Screening Follow up for Mucopolysaccharidosis type II
Special Instructions
- Informed Consent for Genetic Testing
- Biochemical Genetics Patient Information
- Blood Spot Collection Card-Spanish Instructions
- Blood Spot Collection Card-Chinese Instructions
- Informed Consent for Genetic Testing (Spanish)
- Blood Spot Collection Instructions
- Newborn Screening Follow-up for Mucopolysaccharidosis type II
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Iduronate-2-sulfatase, BSSpecimen Type
Whole bloodSpecimen Minimum Volume
Blood Spots: 1
Whole Blood: 0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Whole blood | Varies |
Reference Values
>4.30 nmol/mL/hour
An interpretive report will be provided.
Interpretation
Abnormal results are not sufficient to establish a diagnosis of a particular disease. To verify a preliminary diagnosis based on this assay, additional biochemical or molecular genetic analyses are required.
When abnormal results are detected, a detailed interpretation is given, including an overview of the results and of their significance, a correlation to available clinical information, elements of differential diagnosis, recommendations for additional biochemical testing, and in vitro, confirmatory studies (enzyme assay, molecular genetic analysis), and a phone number to reach one of the laboratory directors in case the referring physician has additional questions.
Clinical Reference
1. Neufeld EF, Muenzer J. The mucopolysaccharidoses. In: Valle DL, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA. eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill; Accessed May 24, 2023. https://ommbid.mhmedical.com/content.aspx?bookid=2709§ionid=225544161
2. Hopwood JJ, Ballabio A. Multiple sulfatase deficiency and the nature of the sulfatase family. In: Valle DL, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA. eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill; Accessed May 24, 2023. https://ommbid.mhmedical.com/content.aspx?bookid=2709§ionid=225546905
Day(s) Performed
Thursday
Report Available
8 to 15 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
82657
83864 (if appropriate)
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
I2SB | Iduronate-2-sulfatase, BS | 79462-8 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
BG749 | Reason for Referral | 42349-1 |
618290 | Iduronate-2-sulfatase | 79462-8 |
618417 | Interpretation | 59462-2 |
618416 | Reviewed By | 18771-6 |