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HelpTest Code Oxysterols Oxysterols, Plasma
Useful For
Investigating a possible diagnosis of Niemann-Pick disease types A, B, or C using plasma specimens
Monitoring of individuals with Niemann-Pick type C disease
This test is not useful for the identification of carriers.
Order: Oxysterols, Plasma
Reporting Name
Oxysterols, PSpecimen Type
PlasmaOrdering Guidance
This test is also available as a part of a panel; see HSMP / Hepatosplenomegaly Panel, Plasma. If this test (OXNP) is ordered with either GPSYP / Glucopsychosine, Plasma or CTXP / Cerebrotendinous Xanthomatosis, Plasma, the individual tests will be canceled and HSMP ordered.
Specimen Required
Supplies: Sarstedt Aliquot Tube 5 mL (T914)
Collection Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Green top (sodium heparin or lithium heparin), yellow top (ACD B)
Submission Container/Tube: Plastic vial
Specimen Volume: 0.3 mL
Collection Instructions:
1. Centrifuge at 4° C.
2. Aliquot plasma into plastic vial. Do not disturb the buffy coat layer.
3. Send frozen.
Collect 2.0 mL whole blood
Specimen Minimum Volume
0.25 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Plasma | Frozen | 65 days |
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | OK |
Reference Values
Cholestane-3-beta,5-alpha,6-beta-triol
Cutoff: ≤0.070 nmol/mL
7-Ketocholesterol
Cutoff: ≤0.100 nmol/mL
Lyso-sphingomyelin
Cutoff :≤ 0.100 nmol/mL
Method Description
An internal standard is added to an aliquot of plasma, which is then subjected to protein precipitation. Following centrifugation, the supernatant is subjected to liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. The MS/MS is operated in the multiple reaction monitoring positive mode to follow the precursor to product species transitions for each analyte and internal standard. The ratio of the extracted peak areas to internal standard determined by the LC-MS/MS is used to calculate the concentration of in the sample.(Unpublished Mayo method)
Day(s) Performed
Tuesday, Thursday
TAT: 4 - 10 days
Report Available
3 to 7 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test 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
82542
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| OXNP | Oxysterols, P | 92740-0 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 36433 | Interpretation (OXNP) | 59462-2 |
| 36430 | Cholestane-3beta,5alpha,6beta-triol | 92755-8 |
| 36431 | 7-Ketocholesterol | 92764-0 |
| 36432 | Lyso-sphingomyelin | 92747-5 |
| 36434 | Reviewed By | 18771-6 |
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Special Instructions
Forms
If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.
Testing Algorithm
For more information see Newborn Screen Follow-up for Acid Sphingomyelinase Deficiency
If the patient has abnormal newborn screening results for Niemann- Pick disease, refer to the appropriate American College of Medical Genetics and Genomics Newborn Screening ACT Sheet.(1)