Home
HelpMayo Test ID CAH2T Congenital Adrenal Hyperplasia Newborn Screen, Blood Spot
Necessary Information
Birth weight, time of birth, and gestational age are required.
Specimen Required
Supplies: Card-Blood Spot Collection (Filter Paper) (T493)
Container/Tube:
Preferred: Blood Spot Collection Card
Acceptable: Local newborn screening card, Whatman 903 filter paper, PerkinElmer 226 filter paper, Munktell filter paper
Specimen Volume: 2 Blood spots
Collection Instructions:
1. Do not use device or capillary tube containing EDTA to collect specimen.
2. Completely fill at least 2 circles on the filter paper card (approximately 100 microliters blood per circle).
3. Let blood dry on filter paper at ambient temperature in a horizontal position for a minimum of 3 hours.
4. Do not expose specimen to heat or direct sunlight.
5. Do not stack wet specimens.
6. Keep specimen dry.
Additional Information:
1. For collection instructions, see Blood Spot Collection Instructions
2. For collection instructions in Spanish, see Blood Spot Collection Card-Spanish Instructions (T777)
3. For collection instructions in Chinese, see Blood Spot Collection Card-Chinese Instructions (T800)
Useful For
Second-tier testing of newborns with abnormal screening result for congenital adrenal hyperplasia
Special Instructions
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Portions of this test are covered by patents held by Quest Diagnostics
Reporting Name
CAH Newborn Screen, BSSpecimen Type
Whole bloodSpecimen Minimum Volume
1 Blood spot
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole blood | Ambient (preferred) | 90 days | FILTER PAPER |
| Frozen | 90 days | FILTER PAPER | |
| Refrigerated | 90 days | FILTER PAPER |
Reject Due To
| Blood spot specimen that shows serum rings or has multiple layers | Reject |
| Insufficient specimen | Reject |
| Unapproved filter papers | Reject |
Clinical Information
Congenital adrenal hyperplasia (CAH) is a group of disorders caused by inherited defects in steroid biosynthesis, most commonly, 21-hydroxylase deficiency (approximately 90% of cases) and 11-beta hydroxylase deficiency (approximately 5% of cases). The overall incidence of CAH due to 21-hydroxylase deficiency is approximately 1 in 15,000 live births. Individuals with CAH may present with life-threatening salt-wasting crises in the newborn period and incorrect sex assignment of virilized females, which occurs due to in utero exposure to reduced glucocorticoids and mineralocorticoids and elevated 17-hydroxyprogesterone (17-OHP) and androgens. Hormone replacement therapy, when initiated early, results in a significant reduction in morbidity and mortality. Therefore, newborn screening for CAH is desirable and has been implemented in all 50 states.
Immunoassays are typically used to quantify 17-OHP as a marker for CAH in the newborn screen setting. However, these immunoassays are hampered by cross-reactivity of the antibodies with other steroids, yielding a high rate of false-positive results. Tandem mass spectrometry allows for the simultaneous specific determination of 17-OHP and other steroids, such as androstenedione, cortisol, 11-deoxycortisol, and 21-deoxycortisol. Application of this technology to the determination of steroids in newborn blood spots significantly enhances the correct identification of patients with CAH and reduces the number of false-positive screening results when implemented as a second-tier analysis performed prior to reporting of initial newborn screen results.
Reference Values
17-HYDROXYPROGESTERONE (17-OHP)
<15.1 ng/mL
ANDROSTENEDIONE
<3.1 ng/mL
CORTISOL
Not applicable
11-DEOXYCORTISOL
<15.1 ng/mL
21-DEOXYCORTISOL
<4.1 ng/mL
(17-OHP + ANDROSTENEDIONE)/CORTISOL RATIO
<1.1
Note: Abnormal (17-OHP + Androstenedione)/Cortisol Ratio: ≥1.1 is only applicable when 17-OHP is elevated
11-DEOXYCORTISOL/CORTISOL RATIO
Not applicable
Interpretation
Findings of a 17-hydroxyprogesterone (17-OHP) value greater than 15.0 ng/mL and a high (17-OHP + androstenedione)/cortisol ratio (≥1) are supportive of the initial abnormal newborn screening result.
Findings of an 11-deoxycortisol value greater than 15.0 ng/mL or 21-deoxycortisol greater than 4.0 ng/mL with elevated 17-OHP further support the abnormal newborn screening result and increase the diagnostic specificity. Clinical and laboratory follow-up is strongly recommended.
Cautions
This is a screening test, and while its positive predictive value is significantly higher than that of immunoassays (9.0% versus 0.5%), false-positive results can occur. Follow-up of abnormal results is necessary; order OHPG / 17-Hydroxyprogesterone, Serum and DOCS / 11- Deoxycorticosterone, Serum.
Deoxycorticosterone (DOC) coelutes with 17-OHP. DOC is a precursor of aldosterone in the steroidogenesis pathway. It is not elevated in patients with classic congenital adrenal hyperplasia (CAH) due to 21-alpha-hydroxylase deficiency; indeed, its production is lacking in this deficiency. However, DOC is expected to be elevated in other variants of CAH, specifically 11-alpha-hydroxylase deficiency (which also includes elevations of 11-deoxy) and 17-alpha-hydroxylase/17,20-lyase deficiency (none of the other targeted steroids are elevated in this condition). Therefore, if this assay was applied as a first-tier screening assay, a finding of elevated DOC and/or 17-OHP can uncover clinically relevant variants of CAH that would be confirmed through follow-up testing. Because this assay's goal is to identify patients with CAH but not exclusively 17-alpha-hydroxylase deficiency, the separation of 17-OHP and DOC during screening is not essential and may lead to a quicker diagnosis of at-risk patients for these rarer variants of CAH. However, as a second-tier test performed only when the first-tier test for 17-OHP is abnormal, 17-alpha-hydroxylase/17,20-lyase deficiency will not be uncovered because 17-OHP is not elevated in that condition.
Clinical Reference
1. Claahsen-van der Grinten HL, Speiser PW, et al. Congenital adrenal hyperplasia-Current insights in pathophysiology, diagnostics, and management. Endocr Rev. 2022;43(1):91-159. doi:10.1210/endrev/bnab016
2. Minutti CZ, Lacey JM, Magera MJ, et al. Steroid profiling by tandem mass spectrometry improves the positive predictive value of newborn screening for congenital adrenal hyperplasia. J Clin Endo Met. 2004;89:3687-3693
3. Turcu AF, Auchus RJ. The next 150 years of congenital adrenal hyperplasia. J Steroid Biochem Mol Biol. 2015;153:63-714
4. Witchel SF, Azziz R. Congenital adrenal hyperplasia. Pediatri Adolesc Gynecol. 2011;24:116-126
Method Description
A 1/8-inch disk is punched out of the blood spot into a 96-well filter plate. Internal standards are added to the filter plate. The punched disks are eluted and centrifuged, then dried under nitrogen and reconstituted with water:methanol. Analysis is by electrospray liquid chromatography-tandem mass spectrometry. The concentration of 17-hydroxyprogesterone, androstenedione, cortisol, 11-deoxycortisol, and 21-deoxycortisol are established by comparison of their ion intensity to that of their respective internal standards.(Unpublished Mayo method)
Day(s) Performed
Monday through Saturday
Report Available
1 to 3 daysSpecimen Retention Time
2 yearsPerforming Laboratory
Mayo Clinic Laboratories in Rochester
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
82542
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| CAH2T | CAH Newborn Screen, BS | 57086-1 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 42207 | 17-OH Progesterone | 38473-5 |
| 42208 | Androstenedione | 53343-0 |
| 42209 | Cortisol | 53345-5 |
| 42210 | 11-deoxycortisol | 53338-0 |
| 42211 | 21-deoxycortisol | 53341-4 |
| 42212 | (17OHP+Androstenedione)/Cortisol | 53336-4 |
| 42213 | 11-deoxycortisol/Cortisol | No LOINC Needed |
| BG688 | Birth Weight (grams, XXXX) | 8339-4 |
| BG689 | Time of Birth (24hr time, XX:XX) | 57715-5 |
| BG690 | Gestational Age (weeks, XX.X) | 76516-4 |
| 42206 | Reviewed By | 18771-6 |
| 42214 | Interpretation (CAH2T) | 46758-9 |