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CYP1B1

cytochrome P450 family 1 subfamily B member 1

The CYP1B1 gene provides instructions for an enzyme crucial for metabolic reactions in the body, including those within the eye, and is associated with certain developmental eye conditions. The CYP1B1 gene encodes an enzyme belonging to the cytochrome P450 family, which plays a role in breaking down drugs and producing lipids.

Chromosome 2p22.2 Various HGNC:2597 Tier C
CYP1B1 2p22.2 p arm q arm 2

CYP1B1 is located on the short (p) arm of chromosome 2, at band 2p22.2. Arm ratio per GRCh38 - banding schematic.

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Clinical tests that include this

Carrier Screening panel
CYP1B1 is 1 of 1,008 genes on this panel
Expanded carrier screening for recessive and X-linked conditions

Overview

The CYP1B1 gene, or cytochrome P450 family 1 subfamily B member 1, is vital for producing an enzyme that is part of the cytochrome P450 family. These enzymes are broadly involved in numerous bodily processes, including metabolic reactions that break down drugs and synthesise lipids. The CYP1B1 enzyme specifically helps add oxygen atoms to various molecules within these biochemical pathways.

What the gene does

The enzyme produced from the CYP1B1 gene participates in key metabolic reactions where an oxygen atom is incorporated into other molecules. This process is important for the breakdown of certain substances, such as drugs, and for the production of specific fats. While the precise role of the CYP1B1 enzyme in eye development is still being investigated, it is active in many eye tissues. Research suggests it may contribute to the formation of structures at the front of the eye and could be involved in regulating the fluid pressure inside the eye.

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Chromosome location

The CYP1B1 gene is located on chromosome 2, specifically at position 2p22.2. This genomic location refers to the short (p) arm of chromosome 2, within region 2, band 2, and sub-band 2.

Protein structure

The CYP1B1 protein comprises 543 amino acids. Domain architecture has not been experimentally characterised in detail for this protein.

Key variants

Over 140 different genetic variants within the CYP1B1 gene have been identified. These variants can alter the gene's function, potentially affecting the activity or production of the CYP1B1 enzyme. Such changes are associated with a range of health conditions, particularly those affecting eye development.

The table below shows the top 10 pathogenic or likely-pathogenic variants currently classified in ClinVar for CYP1B1.
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.1044-1G>C
single nucleotide variant
 - Pathogenic ★★★☆ CYP1B1-related glaucoma with or without anterior segment dysgenesis
c.1044-2A>G
single nucleotide variant
 - Pathogenic ★★★☆ CYP1B1-related glaucoma with or without anterior segment dysgenesis
c.1063C>T
single nucleotide variant
 p.Arg355Ter Pathogenic ★★★☆ CYP1B1-related glaucoma with or without anterior segment dysgenesis
c.1090G>A
single nucleotide variant
 p.Val364Met Pathogenic ★★★☆ CYP1B1-related glaucoma with or without anterior segment dysgenesis
c.1168C>A
single nucleotide variant
 p.Arg390Ser Pathogenic ★★★☆ CYP1B1-related glaucoma with or without anterior segment dysgenesis
c.1454C>T
single nucleotide variant
 p.Ser485Phe Pathogenic ★★★☆ CYP1B1-related glaucoma with or without anterior segment dysgenesis
c.1568G>C
single nucleotide variant
 p.Arg523Thr Pathogenic ★★★☆ CYP1B1-related glaucoma with or without anterior segment dysgenesis
c.317C>A
single nucleotide variant
 p.Ala106Asp Pathogenic ★★★☆ CYP1B1-related glaucoma with or without anterior segment dysgenesis
c.784G>T
single nucleotide variant
 p.Glu262Ter Pathogenic ★★★☆ CYP1B1-related glaucoma with or without anterior segment dysgenesis
c.797GCAACTTCA[1]
Microsatellite
 p.Ser269_Phe271del Pathogenic ★★★☆ CYP1B1-related glaucoma with or without anterior segment dysgenesis

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 CYP1B1 gene are primarily associated with inherited eye conditions. Notably, they are a significant cause of primary congenital glaucoma, a condition characterised by increased eye pressure that can lead to optic nerve damage. Certain CYP1B1 variants are also linked to Peters anomaly, which involves abnormal development of the front structures of the eye and clouding of the cornea.

  • Primary congenital glaucoma
    Ophthalmology
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UK clinical status

The CYP1B1 gene is recognised within the UK's NHS Genomic Medicine Service. It is included on several PanelApp panels, indicating its clinical relevance for genetic testing in specific conditions. These panels include DDG2P, Foetal anomalies (R21), Glaucoma (developmental), and Structural eye disease (R36).

Green-listed
High evidence · clinically actionable in NHS testing
Included in NHS GMS signed-off panels
Fetal anomalies · R21 NHS GMS → Structural eye disease · R36 NHS GMS → DDG2P 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 function of the CYP1B1 gene?

The CYP1B1 gene provides instructions for an enzyme that plays a role in metabolic processes, specifically by adding oxygen atoms to other molecules. This function is important for breaking down certain substances and producing lipids, with particular activity in the eye.

Which conditions are associated with CYP1B1 gene variants?

Variants in the CYP1B1 gene are primarily associated with primary congenital glaucoma, a type of early-onset glaucoma. They are also linked to Peters anomaly, a rare developmental eye condition.

Is the CYP1B1 gene included in UK genetic testing panels?

Yes, the CYP1B1 gene is listed on several NHS Genomic Medicine Service PanelApp panels. These include panels for DDG2P, Foetal anomalies, Glaucoma (developmental), and Structural eye disease, indicating its importance in diagnostic genetic testing within the UK.

References

  1. Vasiliou V, Gonzalez FJ. Role of CYP1B1 in glaucoma. Annual review of pharmacology and toxicology. 2008. PMID: 17914928
  2. Chavarria-Soley G, Sticht H, Aklillu E. Mutations in CYP1B1 cause primary congenital glaucoma by reduction of either activity or abundance of the enzyme. Human mutation. 2008. PMID: 18470941
  3. Chen Y, Jiang D, Yu L. CYP1B1 and MYOC mutations in 116 Chinese patients with primary congenital glaucoma. Archives of ophthalmology (Chicago, Ill. : 1960). 2008. PMID: 18852424
  4. Vincent A, Billingsley G, Priston M. Further support of the role of CYP1B1 in patients with Peters anomaly. Molecular vision. 2006. PMID: 16735991
  5. Achary MS, Reddy AB, Chakrabarti S. Disease-causing mutations in proteins: structural analysis of the CYP1B1 mutations causing primary congenital glaucoma in humans. Biophysical journal. 2006. PMID: 16963504
  6. Melki R, Colomb E, Lefort N. CYP1B1 mutations in French patients with early-onset primary open-angle glaucoma. Journal of medical genetics. 2004. PMID: 15342693
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 27 September 2026. Content compiled from HGNC · MedlinePlus Genetics · ClinGen · Genomics England PanelApp · NHS National Genomic Test Directory · ClinVar · UniProt · AlphaFold .