CAH (21-Hydroxylase Deficiency) Gene Sequencing

Test Code

16072

CPT Codes
81405

Physician Attestation of Informed Consent

This germline genetic test requires physician attestation that patient consent has been received if ordering medical facility is located in AK, DE, FL, GA, IA, MA, MN, NV, NJ, NY, OR, SD or VT or test is performed in MA.

Preferred Specimen

5 mL whole blood collected in an EDTA (lavender-top), ACD-B (yellow-top) or sodium heparin (green-top) tube

Minimum Volume

3 mL

Instructions

Whole blood: Normal phlebotomy procedure. Specimen stability is crucial. Store and ship ambient immediately. Do not freeze.

Isolated DNA not recommended.
Extracted DNA: Please call 1-866-GENE-INFO (1-866-436-3463) for additional information.

Transport Temperature

Room temperature

Specimen Stability

Room temperature: 14 days
Refrigerated: 14 days
Frozen: Unacceptable

Methodology
Next Generation Sequencing

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by the FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

Set up: As needed; Minimum 1x/week; Report available: 3-5 weeks

Limitations

The CAH rare mutation analysis test will NOT detect the common 390 kb deletion allele or any other deletion or recombination allele. DNA analysis can predict the occurrence of CAH but cannot predict the severity of the condition. Polymorphisms or other benign changes in a person’s DNA may prevent accurate genotyping. CYP21A2 genotypes can be complex and analysis of first degree relatives may be required to fully understand the haplotype or pattern of markers on an individual chromosome.

Reference Range

CYP21A2 Gene

Negative

Clinical Significance

This DNA sequencing test identifies rare variants in the 21-hydroxylase gene known to cause congenital adrenal hyperplasia (CAH). It is used when individuals are known or suspected to have 21-OH pathogenic variants undetectable by tests for common CAH variants (e.g. 14755) in order to: 1) confirm or establish a diagnosis of CAH due to 21-OH deficiency, 2) identify genetic carriers of CAH, 3) evaluate the status of persons at risk to be affected by or carriers of CAH due to family history.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.