Test Code OXNP Oxysterols, Plasma
Reporting Name
Oxysterols, PPerforming Laboratory
Mayo Clinic Laboratories in RochesterUseful 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.
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Ordering 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
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.
Specimen Type
PlasmaSpecimen 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
Interpretation
An elevation of cholestane-3-beta, 5-alpha, 6-beta-triol is highly suggestive of Niemann-Pick disease type C (NPC).
An elevation of lyso-sphingomyelin (LSM) is highly suggestive of Niemann-Pick type A or B (NPA or NPB) disease.
An elevation of LSM 509 is suggestive of NPA, NPB, or NPC disease.
Day(s) Performed
Tuesday, Thursday
Report Available
3 to 7 daysTest 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 |
Forms
If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.
Special Instructions
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)