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Test Code 17PRN Pregnenolone and 17-Hydroxypregnenolone, Serum

Reporting Name

Pregnenolone and 17-OH Pregnenolone

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

An ancillary test for congenital adrenal hyperplasia (CAH), particularly in situations in which a diagnosis of both 21- and 11-hydroxylase deficiency have been ruled out

 

Confirming a diagnosis of 3-beta-hydroxysteroid dehydrogenase deficiency and 17-alpha-hydroxylase deficiency

 

As part of a battery of tests to evaluate women with hirsutism or infertility; both can result from adult-onset CAH

Method Name

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

Portions of this test are covered by patents held by Quest Diagnostics


Specimen 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: Centrifuge and aliquot serum into a plastic vial.


Specimen Type

Serum

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Frozen 28 days

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Reference Values

PREGNENOLONE

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

 

ADULTS

≥18 years: 33-248 ng/dL

 

17-HYDROXYPREGNENOLONE

CHILDREN/ADOLESCENTS*

Males

Premature (26-28 weeks): 1,219-9,799 ng/dL

Premature (29-36 weeks): 346-8,911 ng/dL

Full term (1-5 months): 229-3,104 ng/dL

6 months-364 days: 221-1,981 ng/dL

1-2 years: 35-712 ng/dL

3-6 years: <277 ng/dL

7-9 years: <188 ng/dL

10-12 years: <393 ng/dL

13-15 years: 35-465 ng/dL

16-17 years: 32-478 ng/dL

Tanner Stages

Stage I: <209 ng/dL

Stage II: <356 ng/dL

Stage III: <451 ng/dL

Stage IV-V: 35-478 ng/dL

 

Females

Premature (26-28 weeks): 1,219-9,799 ng/dL

Premature (29-36 weeks): 346-8,911 ng/dL

Full term (1-5 months): 229-3,104 ng/dL

6 months-364 days: 221-1,981 ng/dL

1-2 years: 35-712 ng/dL

3-6 years: <277 ng/dL

7-9 years: <213 ng/dL

10-12 years: <399 ng/dL

13-15 years: <408 ng/dL

16-17 years: <424 ng/dL

Tanner Stages

Stage I: <236 ng/dL

Stage II: <368 ng/dL

Stage III: <431 ng/dL

Stage IV-V: <413 ng/dL

 

ADULTS

Males

≥18 years: 55-455 ng/dL

Females

≥18 years: 31-455 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

 

To convert to nmol/L, multiply the value in ng/dL by 0.03159757.

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 DHEA levels will be increased.

 

In the much less common CYP11A1 variant, androstenedione levels are elevated to a similar extent as seen in CYP21A2 variant, and cortisol also is low, but 17-OHPG is only mildly, if at all, elevated.

 

In the very rare 17-hydroxylase deficiency, androstenedione, all other androgen-precursors (17-alpha-hydroxypregnenolone, 17-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.

Day(s) Performed

Monday, Wednesday, Friday

Report Available

3 to 7 days

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-Pregnenolone

84143-17-Hydroxypregnenolone

LOINC Code Information

Test ID Test Order Name Order LOINC Value
17PRN Pregnenolone and 17-OH Pregnenolone In Process

 

Result ID Test Result Name Result LOINC Value
81151 17-Hydroxypregnenolone, S 6765-2
88645 Pregnenolone, S 2837-3

Profile Information

Test ID Reporting Name Available Separately Always Performed
PREGN Pregnenolone, S Yes Yes
17OHP 17-Hydroxypregnenolone, S Yes Yes

Testing Algorithm

For more information see Steroid Pathways.

Special Instructions