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HelpTest Code PREGN Pregnenolone, Serum
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
Testing Algorithm
For more information see Steroid Pathways.
Performing Laboratory
Mayo Clinic Laboratories in Rochester
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, serum gel tubes should be centrifuged .
2. Within 2 hours of collection, red-top tubes should be centrifuged, and the serum aliquoted into a plastic vial.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Frozen | 28 days |
Special Instructions
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.
Day(s) Performed
Monday, Wednesday, Friday
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
84140
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| PREGN | Pregnenolone, S | 2837-3 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 88645 | Pregnenolone, S | 2837-3 |
Interpretation
The diagnosis and differential diagnosis of congenital adrenal hyperplasia (CAH) always require the measurement of several steroids. Patients with CAH due to steroid 21-hydroxylase gene (CYP21A2) variants usually have very high levels of androstenedione, often 5-fold to 10-fold elevations. 17-Hydroxyprogesterone (17-OHPG) levels are usually even higher, while cortisol levels are low or undetectable. All 3 analytes should be tested.
For the HSD3B2 variant, cortisol, 17-OHPG, and progesterone levels will be decreased; 17-hydroxypregnenolone, pregnenolone, and dehydroepiandrosterone (DHEA) levels will be increased.
In the much less common CYP11A1 variant, androstenedione levels are elevated to a similar extent as in CYP21A2 variant, and cortisol is also low, but OHPG is only mildly, if at all, elevated.
In the very rare 17-alpha-hydroxylase deficiency, androstenedione, all other androgen-precursors (17-alpha-hydroxypregnenolone, OHPG, dehydroepiandrosterone sulfate), androgens (testosterone, estrone, estradiol), and cortisol are low, while production of mineral corticoid and its precursors (particularly pregnenolone, 11-dexycorticosterone, corticosterone, and 18-hydroxycorticosterone) are increased.
For more information see Steroid Pathways.
Clinical Reference
1. Wudy S A, Hartmann M, Svoboda M. Determination of 17-hydroxyprogesterone in plasma by stable isotope dilution/benchtop liquid chromatography-tandem mass spectrometry. Horm Res. 2000;53(2):68-71
2. Therrell BL. Newborn screening for congenital adrenal hyperplasia. Endocrinol Metab Clin North Am. 2001:30(1):15-30
3. Bachega TA, Billerbeck AE, Marcondes JA, et al. Influence of different genotypes on 17-hydroxyprogesterone levels in patients with nonclassical congenital adrenal hyperplasia due to 21-hydroxylase deficiency. Clin Endocrinol (Oxf). 2000:52(5):601-607
4. Kao P, Machacek DA, Magera MJ at al. Diagnosis of adrenal cortical dysfunction by liquid chromatography-tandem mass spectrometry. Ann Clin Lab Sci. 2001;31(2):199-204
5. Sciarra F, Tosti-Croce C, Toscano V. Androgen-secreting adrenal tumors. Minerva Endocrinol. 1995:20(1):63-68
6. Collett-Solberg PF. Congenital adrenal hyperplasia: from genetics and biochemistry to clinical practice, Part 1. Clin Pediatr (Phila). 2001:40(1):1-16
7. Chormanski D, Muzio MR. C 17 hydroxylase deficiency. In: StatPearls [Internet]. StatPearls Publishing; 2021. Updated January 3, 2023. Accessed May 29, 2024. Available at www.ncbi.nlm.nih.gov/books/NBK546644/
Report Available
3 to 7 daysMethod Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)