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Congenital Adrenal Hyperplasia (CAH) due to 11-β-Hydroxylase Deficiency (11-OHD) via the CYP11B1 Gene

Summary and Pricing

Test Method

Bi-Directional Sanger Sequencing
Test Code Test Copy GenesTest CPT Code Gene CPT Codes Copy CPT Codes Base Price
1268 CYP11B1 81405 81405 $870 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
1268CYP11B181405 81405 $870 Order Options and Pricing

An additional 25% charge will be applied to STAT orders. STAT orders are prioritized throughout the testing process.

Turnaround Time

12 days on average for standard orders or 8 days on average for STAT orders.

Please note: Once the testing process begins, an Estimated Report Date (ERD) range will be displayed in the portal. This is the most accurate prediction of when your report will be complete and may differ from the average TAT published on our website. About 85% of our tests will be reported within or before the ERD range. We will notify you of significant delays or holds which will impact the ERD. Learn more about turnaround times here.

Targeted Testing

For ordering sequencing of targeted known variants, go to our Targeted Variants page.

EMAIL CONTACTS

Genetic Counselors

Geneticist

  • Wuyan Chen, PhD

Clinical Features and Genetics

Clinical Features

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders each due to defects in a single gene involved in different steps of cortisol biosynthesis (Nimkarn et al. 2008. PubMed ID: 18294861; Hannah-Shmouni et al. 2017. PubMed ID: 28476231). CAH represents a continuous phenotypic spectrum depending on causative gene, genotype, residual activity and age of presentation. Over 95% of CAH cases are caused by 21- hydroxylase deficiency (21-OHD). The second most common form of CAH is due to 11-hydroxylase deficiency (11-OHD) which accounts for approximately 5% of cases with an incidence of 1 in 100,000 live births.

The classic form of 11-OHD consists of two groups: (1) virilization of the external genitalia in 46,XX newborn females; and (2) precocious pseudopuberty in both sexes. The non-classic form is rare and presents with hyperandrogenism during childhood.

Genetics

CAH due to 11-OHD is an autosomal recessive disorder caused by defects in the CYP11B1 gene (White et al. 1991. PubMed ID: 2022736). Documented pathogenic variants throughout the entire CYP11B1 gene include truncating changes (nonsense, splice variants and frame-shifting small deletion/insertions), missense substitutions and intragenic large deletions (Human Gene Mutation Database). Pathogenic variants clustered in exons 2, 6, 7 and 8 are evident. In addition, due to high sequence similarity to the CYP11B2 gene, which encodes aldosterone synthase, rare chimeric CYP11B2/CYP11B1 genes can also result in CAH due to 11-OHD (Hampf et al. 2001. PubMed ID: 11549691; Duan et al. 2018. PubMed ID: 29703198; Portrat et al. 2001. PubMed ID: 11443188).

The 11-hydroxylase (CYP11B1) enzyme is a P450 type I mitochondrial enzyme responsible for the conversion of 11-deoxycortisol to cortisol, and 11-deoxycorticosterone (DOC) to corticosterone.

Clinical Sensitivity - Sanger Sequencing

In a study of 28 patients from 24 Turkish families affected by 11-hydroxylase deficiency (26 classic and 2 late-onset), using the strategy of specifically amplifying CYP11B1 gene fragments, all patients received a molecular diagnosis (Kandemir et al. 2017. PubMed ID: 26956189). Similar clinical sensitivity was observed by Bas et al. (2018. PubMed ID: 29626607). These studies indicated intragenic large deletions and chimeric CYP11B2/CYP11B1 genes are rare. Therefore, our test is expected to be able to detect the vast majority of pathogenic variants.

Testing Strategy

This test involves bidirectional Sanger sequencing of all coding exons and splice sites of the CYP11B1 gene. The full coding sequence of each exon plus ~10 bp of flanking DNA on either side are sequenced. We will also sequence any single exon (Test #100) or pair of exons (Test #200) in family members of patients with known mutations or to confirm research results.

By using specifically amplifying the CYP11B1 gene (to avoid the paralogous gene CYP11B2), our strategy is NOT designed to detect rare chimeric CYP11B2/CYP11B1 genes. However, our assay is expected to capture the majority of small gene-conversion events.

Indications for Test

Candidates for this test are patients with congenital adrenal hyperplasia (CAH), especially due to 11-hydroxylase deficiency (11-OHD). This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in CYP11B1.

Gene

Official Gene Symbol OMIM ID
CYP11B1 610613
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Citations

  • Bas et al. 2018. PubMed ID: 29626607
  • Duan et al. 2018. PubMed ID: 29703198
  • Hampf et al. 2001. PubMed ID: 11549691
  • Hannah-Shmouni et al. 2017. PubMed ID: 28476231
  • Human Gene Mutation Database (Biobase).
  • Kandemir et al. 2017. PubMed ID: 26956189
  • Nimkarn. 2008. PubMed ID: 18294861
  • Portrat et al. 2001. PubMed ID: 11443188
  • White et al. 1991. PubMed ID: 2022736

Ordering/Specimens

Ordering Options

We offer several options when ordering sequencing tests. For more information on these options, see our Ordering Instructions page. To view available options, click on the Order Options button within the test description.

myPrevent - Online Ordering

  • The test can be added to your online orders in the Summary and Pricing section.
  • Once the test has been added log in to myPrevent to fill out an online requisition form.
  • PGnome sequencing panels can be ordered via the myPrevent portal only at this time.

Requisition Form

  • A completed requisition form must accompany all specimens.
  • Billing information along with specimen and shipping instructions are within the requisition form.
  • All testing must be ordered by a qualified healthcare provider.

For Requisition Forms, visit our Forms page


Specimen Types

Specimen Requirements and Shipping Details

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ORDER OPTIONS

View Ordering Instructions

1) Select Test Method (Backbone)


1) Select Test Type


2) Select Additional Test Options

STAT and Prenatal Test Options are not available with Patient Plus.

No Additional Test Options are available for this test.

Note: acceptable specimen types are whole blood and DNA from whole blood only.
Total Price: $
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