AtlasGene
CYP2C19
cytochrome P450 family 2 subfamily C member 19
- HGNC 2621↗(opens in a new tab)
- Ensembl gene ENSG00000165841↗(opens in a new tab)
- NCBI Gene 1557↗(opens in a new tab)
Summary
- Cytogenetic location
- 10q23.33
- Coordinates
- Chromosome 10: 94,762,681–94,855,547 (GRCh38)
- Exons
- 9 exons across 92.9 kb
- Protein
- 490 amino acids
- Also known as
- P450IIC19, CPCJ
- Previous symbols
- CYP2C
- MANE Select transcript
- ENST00000371321.9NM_000769.4
- Locus type
- Protein-coding
- Very high
- Confident
- Low
- Very low
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Get my Genome TestCYP2C19 and medicines
Antidepressant, stomach-acid & clopidogrel response
Pharmacogenomics
CYP2C19 clears several common antidepressants (citalopram, escitalopram, sertraline and some tricyclics), the proton-pump inhibitors used for reflux and ulcers, and the antifungal voriconazole — and it activates the antiplatelet clopidogrel into its working form. Activity ranges from poor to ultrarapid depending on which alleles you carry.
- Most relevant if you are prescribed clopidogrel after a stent, heart attack, or stroke — poor metabolisers may get little protection from it.
- If you start citalopram, escitalopram or sertraline, this result can guide the starting dose, and can help explain side effects or a weak response.
- Omeprazole, lansoprazole and pantoprazole may work less well in rapid and ultrarapid metabolisers; poor metabolisers on long-term treatment may manage on a lower dose.
- Also relevant to voriconazole, amitriptyline and other tricyclic antidepressants, and the anti-seizure drug clobazam.
Alleles the report reads
- *4No function
- *1Normal function
- *17Increased function
- *3No function
- *2No function
Results CPIC describes
- Poor Metabolizer
- Intermediate Metabolizer
- Indeterminate
- Likely Intermediate Metabolizer
- Rapid Metabolizer
- Normal Metabolizer
- Ultrarapid Metabolizer
- Likely Poor Metabolizer
Medicine CPIC level Guideline amitriptyline A CYP2D6, CYP2C19 and Tricyclic Antidepressants citalopram A CYP2D6, CYP2C19, CYP2B6, SLC6A4, HTR2A and Serotonin Reuptake Inhibitor Antidepressants clopidogrel A CYP2C19 and Clopidogrel escitalopram A CYP2D6, CYP2C19, CYP2B6, SLC6A4, HTR2A and Serotonin Reuptake Inhibitor Antidepressants lansoprazole A CYP2C19 and Proton Pump Inhibitors omeprazole A CYP2C19 and Proton Pump Inhibitors pantoprazole A CYP2C19 and Proton Pump Inhibitors sertraline A CYP2D6, CYP2C19, CYP2B6, SLC6A4, HTR2A and Serotonin Reuptake Inhibitor Antidepressants voriconazole A CYP2C19 and Voriconazole brivaracetam B clomipramine B CYP2D6, CYP2C19 and Tricyclic Antidepressants dexlansoprazole B CYP2C19 and Proton Pump Inhibitors doxepin B CYP2D6, CYP2C19 and Tricyclic Antidepressants imipramine B CYP2D6, CYP2C19 and Tricyclic Antidepressants trimipramine B CYP2D6, CYP2C19 and Tricyclic Antidepressants Show 12 more medicines
Medicine CPIC level Guideline carisoprodol B/C clobazam B/C diazepam B/C duloxetine C CYP2D6, CYP2C19, CYP2B6, SLC6A4, HTR2A and Serotonin Reuptake Inhibitor Antidepressants esomeprazole C CYP2C19 and Proton Pump Inhibitors flibanserin C fluoxetine C CYP2D6, CYP2C19, CYP2B6, SLC6A4, HTR2A and Serotonin Reuptake Inhibitor Antidepressants fluvoxamine C CYP2D6, CYP2C19, CYP2B6, SLC6A4, HTR2A and Serotonin Reuptake Inhibitor Antidepressants paroxetine C CYP2D6, CYP2C19, CYP2B6, SLC6A4, HTR2A and Serotonin Reuptake Inhibitor Antidepressants rabeprazole C CYP2C19 and Proton Pump Inhibitors venlafaxine C CYP2D6, CYP2C19, CYP2B6, SLC6A4, HTR2A and Serotonin Reuptake Inhibitor Antidepressants vortioxetine C CYP2D6, CYP2C19, CYP2B6, SLC6A4, HTR2A and Serotonin Reuptake Inhibitor Antidepressants Calls the common *2, *3, *4 and *17 alleles. CYP2C19 lacks the copy-number complexity of CYP2D6, so common-allele calling is well supported — but rare alleles are not assessed.
How CYP2C19 is laid out
- Coding sequence
- Untranslated region
- Intron
- Direction of transcription
- Stretches short reads find hard
Exons of the gene's MANE Select transcript (release v1.5), from NCBI and EMBL-EBI, on the GRCh38 reference genome.
Chromosome bands from UCSC's GRCh38 ideogram (2022-10-29).
Nearby genes from Ensembl release 116, on GRCh38.
Exons make up 4.1 kb of the gene's 92.9 kb; 1,473 of those bases code for the protein.
Sequencing CYP2C19
2Low
How hard CYP2C19 is to sequence with short reads, out of 100Each bar is the share of CYP2C19's exon bases in that kind of difficult region. The score weighs them by how much each costs a short-read call: 0 when no base is in any, 100 when every base is in all of them.
- MappabilityStretches where 100 or 250 bp reads cannot be placed uniquely, so a call there may be missing or wrong. Weight 35%.2.5%
- HomologySegmental duplications: copies elsewhere in the genome, such as paralogues and pseudogenes, at 90% identity or more. Weight 30%.0%
- RepeatsTandem repeats and runs of one base, which reads slip on and may not span. Weight 15%.4.9%
- GC contentWindows under 25% or over 65% G and C, which library preparation covers thinly. Weight 10%.1.6%
- Reference coverageGaps in the reference assembly nearby, where there is no sequence for reads to align to. Weight 10%.0%
External links
Gene records
Transcript
Protein
Where this comes from
- HGNC: the gene's symbol, name, other symbols and location.
- MANE Select v1.5, from NCBI and EMBL-EBI: the transcript, its exons and coding sequence.
- The Genome in a Bottle genome stratifications, from NIST: the sequencing difficulty score.
- CPIC and PharmGKB: the alleles, results and medicines.
Cite this page
Dante Labs. (n.d.). CYP2C19 gene: cytochrome P450 family 2 subfamily C member 19. Retrieved 17 October 2026, from https://dantelabs.com/genes/cyp2c19
Dante Labs. CYP2C19 gene: cytochrome P450 family 2 subfamily C member 19 [Internet]. [cited 17 October 2026]. Available from: https://dantelabs.com/genes/cyp2c19
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