Test Code OXYWB Oxysterols, Blood
Ordering Guidance
Based on internal validation studies, this test using dried blood spots created from a whole blood specimen is less clinically sensitive and specific for diagnosing Niemann-Pick type C (NPC) (75% and 89%, respectively) than using plasma (98%). If there is a strong clinical suspicion for NPC, order OXNP / Oxysterols, Plasma.
This test is also available as a part of a panel, see HSMWB / Hepatosplenomegaly Panel, Blood. If this test (OXYWB) is ordered with either GPSYW / Glucopsychosine, Blood or CTXWB / Cerebrotendinous Xanthomatosis, Blood, the individual tests will be canceled and HSMWB ordered.
Specimen Required
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Green top (sodium heparin, lithium heparin) or yellow top (ACD B)
Specimen Volume: 1 mL
Collection Instructions: Send whole blood specimen in original tube. Do not aliquot.
Forms
If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.
Secondary ID
113429Useful For
Investigating a possible diagnosis of acid sphingomyelinase deficiency, also known as Niemann-Pick disease type A or B, using dried blood spots created from a whole blood specimen
This test is not recommended for diagnosis of Niemann-Pick type C (NPC). If NPC is suspected, consider plasma oxysterols.
This test is not useful for the identification of carriers
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Oxysterols, BSpecimen Type
Whole bloodSpecimen Minimum Volume
0.25 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole blood | Refrigerated (preferred) | 72 hours |
| Ambient | 48 hours |
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | OK |
Reference Values
Cholestane-3-beta,5-alpha,6-beta-triol
Cutoff: ≤0.800 nmol/mL
Lyso-sphingomyelin
Cutoff: ≤0.100 nmol/mL
Day(s) Performed
Tuesday, Thursday
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 |
|---|---|---|
| OXYWB | Oxysterols, B | 92738-4 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| BA4354 | Interpretation (OXYWB) | 59462-2 |
| BA4352 | Cholestane-3beta,5alpha,6beta-triol | 92756-6 |
| BA4353 | Lyso-sphingomyelin | 92748-3 |
| BA4355 | Reviewed By | 18771-6 |
Testing Algorithm
If the patient has abnormal newborn screening results for acid sphingomyelinase deficiency, also called Niemann-Pick type A or B disease, refer to the appropriate American College of Medical Genetics and Genomics Newborn Screening ACT Sheet.(1)