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Test ID: 17PRN Pregnenolone and 17-Hydroxypregnenolone, Serum

Reporting Name

Pregnenolone and 17-OH Pregnenolone

Useful For

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

 

Confirming a diagnosis of 3-beta-hydroxy dehydrogenase (3-beta-HSD) deficiency and 17-alpha-hydroxylase deficiency.

 

Analysis for 17-hydroxypregnenolone is also useful as part of a battery of tests to evaluate females with hirsutism or infertility. Both can result from adult-onset CAH.

Clinical Information

Congenital adrenal hyperplasia (CAH) is caused by inherited defects in steroid biosynthesis. Deficiencies in several enzymes cause CAH including 21-hydroxylase (CYP21A2 mutations; 90% of cases), 11-hydroxylase (CYP11A1 mutations; 5%-8%), 3-beta-hydroxy dehydrogenase (HSD3B2 mutations; <5%), and 17-alpha-hydroxylase (CYP17A1 mutations; 125 cases reported to date). The resulting hormone imbalances (reduced glucocorticoids and mineralocorticoids, and elevated steroid intermediates and androgens) can lead to life-threatening, salt-wasting crises in the newborn period and incorrect gender assignment of virilized females.

 

The adrenal glands, ovaries, testes, and placenta produce steroid intermediates, which are hydroxylated at position 21 (by 21-hydroxylase) and position 11 (by 11-hydroxylase) to produce cortisol. Deficiency of either 21-hydroxylase or 11-hydroxylase results in decreased cortisol synthesis and loss of feedback inhibition of adrenocorticotropic hormone (ACTH) secretion. The consequent increased pituitary release of ACTH drives increased production of steroid intermediates.

 

The steroid intermediates are oxidized at position 3 (by 3-beta-hydroxy dehydrogenase [3-beta-HSD]). The 3-beta-HSD enzyme allows formation of 17-hydroxyprogesterone (17-OHPG) from 17-hydroxypregnenolone and progesterone from pregnenolone. When 3-beta-HSD is deficient, cortisol is decreased, 17-hydroxypregnenolone and pregnenolone levels may increase, and 17-OHPG and progesterone levels, respectively, are low. Dehydroepiandrosterone is also converted to androstenedione by 3-beta-HSD, and may be elevated in patients affected with 3-beta-HSD deficiency.

 

The best screening test for CAH, most often caused by either 21- or 11-hydroxylase deficiency, is the analysis of 17-hydroxyprogesterone (along with cortisol and androstenedione). CAH21 / Congenital Adrenal Hyperplasia (CAH) Profile for 21-Hydoxylase Deficiency allows the simultaneous determination of these 3 analytes. Alternately, these tests may be ordered individually: OHPG / 17-Hydroxyprogesterone, Serum; CINP / Cortisol, Serum, LC-MS/MS; and ANST / Androstenedione, Serum.

 

If both 21- and 11-hydroxylase deficiency have been ruled out, analysis of 17-hydroxypregnenolone and pregnenolone may be used to confirm the diagnosis of 3-beta-HSD or 17-alpha-hydroxylase deficiency.

 

See Steroid Pathways in Special Instructions.

Interpretation

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) mutations usually have very high levels of androstenedione, often 5-fold to 10-fold elevations. 17-OHPG levels are usually even higher, while cortisol levels are low or undetectable. All 3 analytes should be tested.

 

For the HSD3B2 mutation, cortisol, 17-OHPG and progesterone levels will be will be decreased; 17-hydroxypregnenolone and pregnenolone and DHEA levels will be increased.

 

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

 

In the also 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 (in particular pregnenolone, 11-dexycorticosterone, corticosterone, and 18-hydroxycorticosterone) are increased.

 

See Steroid Pathways in Special Instructions.

Testing Algorithm

See Steroid Pathways in Special Instructions.

Profile Information

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

Special Instructions

Analytic Time

2 days

Day(s) and Time(s) Performed

Monday, Tuesday, Thursday; 8 a.m.

Clinical Reference

1. Wudy S A, Hartmann M, Svoboda M: Determination of 17-hydroxypregnenolone in plasma by stabile 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 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 I. Clin Pediatr 2001:40(1):1-16

Method Name

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

Portions of this test are covered by patent(s) held by Quest Diagnostics

Specimen Type

Serum


Specimen Required


Collection Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Frozen 28 days

Reference Values

PREGNENOLONE

CHILDREN*

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

*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

 

17-HYDROXYPREGNENOLONE

CHILDREN*

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

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

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
Mayo Clinic Laboratories | Endocrinology Catalog Additional Information:

mml-adrenal-gonad-pituitary