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HelpOrder Code PREGN Pregnenolone, Serum
Additional Codes
| Mayo Test ID |
|---|
| PREGN |
Reporting Name
Pregnenolone, SUseful For
An ancillary test for congenital adrenal hyperplasia, particularly in situations in which a diagnosis of both 21- and 11-hydroxylase deficiency have been ruled out
Confirming a diagnosis of 3-beta-hydroxy dehydrogenase deficiency
Specimen Type
SerumSpecimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Within 2 hours of collection, centrifuge the specimen and immediately aliquot serum into a plastic vial.
2. Freeze immediately.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum | Frozen | 28 days |
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | OK |
Reference Values
CHILDREN/ADOLESCENTS*
Males
0-6 years: Not established
7-9 years: <206 ng/dL
10-12 years: <152 ng/dL
13-15 years: 18-197 ng/dL
16-17 years: 17-228 ng/dL
Tanner Stages
Stage I: <157 ng/dL
Stage II: <144 ng/dL
Stage III: <215 ng/dL
Stage IV-V: 19-201 ng/dL
Females
0-6 years: Not established
7-9 years: <151 ng/dL
10-12 years: 19-220 ng/dL
13-15 years: 22-210 ng/dL
16-17 years: 22-229 ng/dL
Tanner Stages
Stage I: <172 ng/dL
Stage II: 22-229 ng/dL
Stage III: 34-215 ng/dL
Stage IV-V: 26-235 ng/dL
*Kushnir MM, Rockwood AL, Roberts WL, et al. Development and performance evaluation of a tandem mass spectrometry assay for 4 adrenal steroids. Clin Chem. 2006;52(8):1559-1567
ADULTS
≥18 years: 33-248 ng/dL
To convert to nmol/L, multiply the value in ng/dL by 0.03159757.
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Day(s) Performed
Monday through Wednesday, Friday
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
CPT Code Information
84140
Testing Algorithm
For more information see Steroid Pathways.
Special Instructions
Method Description
Deuterium-labeled internal standards (pregnenolone-d4 and 17-hydroxypregnenolone-d3) are added to 0.2 mL of sample. Pregnenolone, 17-hydroxypregnenolone and the internal standards are extracted from the sample using solid phase extraction. The extracts are then washed and dried under nitrogen. Extracts are then derivatized using hydroxylamine and analyzed by liquid chromatography tandem mass spectrometry. The mass spectrometer has an electrospray interface and is operated in the multiple-reaction monitoring positive mode. A 6-point standard curve is extracted and derivatized with each batch of samples.(Unpublished Mayo method)