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CYP11B1

cytochrome P450 family 11 subfamily B member 1

The CYP11B1 gene encodes the 11-beta-hydroxylase enzyme, which plays a vital role in the adrenal glands' production of steroid hormones such as cortisol and corticosterone. CYP11B1 provides instructions for making 11-beta-hydroxylase, an enzyme found in the adrenal glands.

Chromosome 8q24.3 Various HGNC:2591 Tier C
CYP11B1 8q24.3 p arm q arm 8

CYP11B1 is located on the long (q) arm of chromosome 8, at band 8q24.3. Arm ratio per GRCh38 - banding schematic.

Explore chromosome 8 in the library →

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Clinical tests that include this

Carrier Screening panel
CYP11B1 is 1 of 1,008 genes on this panel
Expanded carrier screening for recessive and X-linked conditions
Newborn Genetic Screening panel
CYP11B1 is 1 of 258 genes on this panel
Genomic newborn screening for actionable paediatric conditions

Overview

The CYP11B1 gene, also known as cytochrome P450 family 11 subfamily B member 1, is crucial for adrenal gland function. It produces an enzyme called 11-beta-hydroxylase, which is part of the cytochrome P450 enzyme family.

This enzyme plays a central role in the body's endocrine system by facilitating the creation of steroid hormones. Variations within the CYP11B1 gene are associated with inherited conditions affecting hormone production.

What the gene does

The CYP11B1 gene provides the blueprint for 11-beta-hydroxylase, an enzyme located in the adrenal glands. As a member of the cytochrome P450 enzyme family, 11-beta-hydroxylase is involved in various metabolic processes within cells.

Its primary function is to convert specific precursor molecules into cortisol and corticosterone. Specifically, it transforms 11-deoxycortisol into cortisol and 11-deoxycorticosterone into corticosterone. These conversions are stimulated by adrenocorticotropic hormone (ACTH) released from the pituitary gland.

Cortisol helps maintain blood glucose levels, protects the body from physical stress, and reduces inflammation. Corticosterone is further processed into aldosterone by another enzyme, aiding in blood pressure regulation by balancing salt and fluid levels.

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Chromosome location

The CYP11B1 gene is situated on chromosome 8, specifically at position 8q24.3. This chromosomal location indicates its precise address within the human genome. The gene provides instructions for a protein comprising 503 amino acids.

Protein structure

Domain architecture has not been experimentally characterised in detail for this protein.

Key variants

Genetic changes or variants within the CYP11B1 gene can alter the function of the 11-beta-hydroxylase enzyme. These alterations can lead to a reduction or loss of enzymatic activity, impacting the body's ability to produce essential steroid hormones. Different types of variants, including those that change single protein building blocks, have been identified.

The table below shows the top 10 pathogenic or likely-pathogenic variants currently classified in ClinVar for CYP11B1.
View all on ClinVar →

Sample of pathogenic variants

10 pathogenic / likely-pathogenic variants from ClinVar, ranked by review status (expert-panel-reviewed first). This is a sample; recurrent founder variants in a specific population may not appear here - see the full ClinVar listing via the link above.

Variant (HGVS) Protein change Classification Evidence Associated condition
c.124C>T
single nucleotide variant
 p.Pro42Ser Pathogenic/Likely pathogenic ★★☆☆ Glucocorticoid-remediable aldosteronism
c.217C>T
single nucleotide variant
 p.Gln73Ter Pathogenic ★★☆☆ Deficiency of steroid 11-beta-monooxygenase
c.235T>A
single nucleotide variant
 p.Phe79Ile Pathogenic/Likely pathogenic ★★☆☆ Differences in sex development
c.281C>T
single nucleotide variant
 p.Pro94Leu Pathogenic ★★☆☆ Glucocorticoid-remediable aldosteronism
c.317_344del
Deletion
 p.Leu106fs Pathogenic ★★☆☆ Deficiency of steroid 11-beta-monooxygenase
c.348G>C
single nucleotide variant
 p.Trp116Cys Pathogenic ★★☆☆ Congenital adrenal hyperplasia
g.(?_143955789)_(143961229_?)del
Deletion
 - Pathogenic ★☆☆☆ not provided
c.239+1G>C
single nucleotide variant
 - Pathogenic ★☆☆☆ Deficiency of steroid 11-beta-monooxygenase
c.348G>A
single nucleotide variant
 p.Trp116Ter Pathogenic ★☆☆☆ Differences in sex development
c.359_360dup
Duplication
 p.Gln121fs Pathogenic ★☆☆☆ Differences in sex development

Evidence stars indicate ClinVar review status. Individual variant interpretation should always be performed by a qualified clinical laboratory - many variants remain classified as Variants of Uncertain Significance (VUS) pending more research.

Associated conditions

Variants in the CYP11B1 gene are primarily associated with conditions that affect adrenal hormone production. These include Congenital adrenal hyperplasia (11-hydroxylase), where the adrenal glands produce an excess of male sex hormones, and Familial hyperaldosteronism type I (GRA), which can lead to high blood pressure due to a genetic rearrangement involving this gene.

UK clinical status

The CYP11B1 gene is recognised in the UK by NHS England's National Genomic Test Directory. It is included on green-rated gene panels for 'Differences in sex development' (R146), 'Extreme early-onset hypertension', and 'Foetal anomalies' (R21), indicating its clinical relevance for these conditions.

Green-listed
High evidence · clinically actionable in NHS testing
Included in NHS GMS signed-off panels
Differences in sex development · R146 NHS GMS → Fetal anomalies · R21 NHS GMS →
NHS Genomic Medicine Service Jeen carrier screening

Sources: NHS GMS PanelApp · Genomics England PanelApp · NHS National Genomic Test Directory

Frequently asked questions

What is the main role of the CYP11B1 gene?

The CYP11B1 gene provides instructions for the 11-beta-hydroxylase enzyme, which is essential for producing the steroid hormones cortisol and corticosterone in the adrenal glands.

Which conditions are associated with CYP11B1 gene variants?

Variants in the CYP11B1 gene are linked to conditions such as Congenital adrenal hyperplasia (11-hydroxylase), which involves excess male sex hormone production, and Familial hyperaldosteronism type I (GRA), which can cause high blood pressure.

Where is the CYP11B1 gene located?

The CYP11B1 gene is found on chromosome 8, specifically at band 8q24.3.

References

  1. Moraitis AG, Rainey WE, Auchus RJ. Gene mutations that promote adrenal aldosterone production, sodium retention, and hypertension. The application of clinical genetics. 2013. PMID: 24399884
  2. Parajes S, Loidi L, Reisch N. Functional consequences of seven novel mutations in the CYP11B1 gene: four mutations associated with nonclassic and three mutations causing classic 11{beta}-hydroxylase deficiency. The Journal of clinical endocrinology and metabolism. 2010. PMID: 20089618
  3. Quack I, Vonend O, Rump LC. Familial hyperaldosteronism I-III. Hormone and metabolic research = Hormon- und Stoffwechselforschung = Hormones et metabolisme. 2010. PMID: 20131203
  4. Martinez-Aguayo A, Fardella C. Genetics of hypertensive syndrome. Hormone research. 2009. PMID: 19339789
  5. Nimkarn S, New MI. Steroid 11beta- hydroxylase deficiency congenital adrenal hyperplasia. Trends in endocrinology and metabolism: TEM. 2008. PMID: 18294861
  6. Williams SS. Advances in genetic hypertension. Current opinion in pediatrics. 2007. PMID: 17496764
  7. Stowasser M, Gordon RD. Monogenic mineralocorticoid hypertension. Best practice & research. Clinical endocrinology & metabolism. 2006. PMID: 16980202
  8. Peter M. Congenital adrenal hyperplasia: 11beta-hydroxylase deficiency. Seminars in reproductive medicine. 2002. PMID: 12428205
  9. Stowasser M, Gordon RD. Familial hyperaldosteronism. The Journal of steroid biochemistry and molecular biology. 2001. PMID: 11595502
  10. Stowasser M, Gunasekera TG, Gordon RD. Familial varieties of primary aldosteronism. Clinical and experimental pharmacology & physiology. 2001. PMID: 11903322
Educational content. This page is not medical or genetic advice, is not individually reviewed by a clinician for each reader, and should not replace a consultation with a qualified healthcare professional or genetic counsellor. If you are considering genetic testing or acting on a test result, book a consultation.
Data sources Last updated 18 October 2026. Content compiled from HGNC · MedlinePlus Genetics · ClinGen · Genomics England PanelApp · NHS National Genomic Test Directory · ClinVar · UniProt · AlphaFold .