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Test Code OXNP Oxysterols, Plasma

Reporting Name

Oxysterols, P

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Investigation of possible diagnoses of Niemann-Pick disease types A, B, or C in plasma specimens


Monitoring of individuals with NPC disease

Method Name

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Specimen Required

Collection Container/Tube:

Preferred: Lavender top (EDTA)

Acceptable: Sodium heparin, lithium heparin, or ACD B

Submission Container/Tube: Plastic vial

Specimen Volume: 0.3 mL

Specimen Type


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


Cutoff: ≤0.070 nmol/mL



Cutoff: ≤0.100 nmol/mL



Cutoff :≤ 0.100 nmol/mL


An elevation of cholestane-3-beta, 5-alpha, 6-beta-triol (COT) 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 lyso-sphingomyelin 509 (LSM 509) is suggestive of NPA, NPB, or NPC disease.

Day(s) and Time(s) Performed

Tuesday; 8 a.m.

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information


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


If not ordering electronically, complete, print, and send an Inborn Errors of Metabolism Test Request (T798) with the specimen.