CYP2C9

Chr 10

cytochrome P450 family 2 subfamily C member 9

Also known as: CPC9, CYP2C, CYP2C10, CYPIIC9, P450-2C9, P450IIC9

This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This protein localizes to the endoplasmic reticulum and its expression is induced by rifampin. The enzyme is known to metabolize many xenobiotics, including phenytoin, tolbutamide, ibuprofen and S-warfarin. Studies identifying individuals who are poor metabolizers of phenytoin and tolbutamide suggest that this gene is polymorphic. The gene is located within a cluster of cytochrome P450 genes on chromosome 10q24. [provided by RefSeq, Jul 2008]

GeneReviewsResearchGenerating clinical summary…
12
Active trials
402
Pubs (1 yr)
P/LP submissions
P/LP missense
1.40
LOEUF
Multiple*
Mechanism· predicted
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GeneReview available — CYP2C9
Authoritative clinical overview · Recommended first read
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Some data sources returned errors (1)

omim: Error: OMIM fetch failed: 429

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint?
1.40LOEUF
pLI 0.000
Z-score 0.29
OE 0.92 (0.621.40)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?
-2.94Z-score
OE missense 1.52 (1.401.66)
381 obs / 250.3 exp
Tolerant

Tolerant to missense variation

Observed / Expected Ratios?
LoF OE?0.92 (0.621.40)
00.351.4
Missense OE?1.52 (1.401.66)
00.61.4
Synonymous OE?1.54
01.21.6
LoF obs/exp: 16 / 17.3Missense obs/exp: 381 / 250.3Syn Z: -4.07

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

CYP2C9 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

PRS-based Primary Prevention of CVD

Polygenic Risk Driven Pragmatic Statin Trial for Heart Disease Prevention

ACTIVE NOT RECRUITING
NCT06820086Phase PHASE4Mikk JÜRISSONStarted 2025-03-26
Rosuvastatin 20mg
NSCLC (Non-small Cell Lung Cancer)Thyroid CancerSolid Tumor Malignancies

Pralsetinib DDI Study in Patients With Advanced or Metastatic Solid Tumors

RECRUITING
NCT07704658Phase PHASE4Rigel PharmaceuticalsStarted 2026-03-04
PralsetinibCYP3A4, CYP2C8, and CYP2C9 substrates, and hormonal contraceptive
Pharmacokinetics of Celecoxib in Children

CELECOXIB Plasma and Cerebral Spinal Fluid Pharmacokinetics in Children

RECRUITING
NCT01344200Phase PHASE2Children's Hospital of Eastern OntarioStarted 2024-01-29
CelecoxibPlacebo
Driving Under the Influence of Cannabis

Pilot-Study for the Comparison of Biomarkers Between Regular Cannabis Users and Non-Users

RECRUITING
NCT06975020Phase NAUniversity of BaselStarted 2025-12-19
Participants will prepare their cannabis product ad libitum and inhale the prepared product as usual for a maximum of 15 minutes.
SeizuresTraumatic Brain InjuriesTraumatic Brain Injury (TBI) Patients

Early Post-Traumatic Seizures Prevention Trial (E-PTS Trial)

RECRUITING
NCT07072624Phase PHASE4All India Institute of Medical Sciences, JodhpurStarted 2025-07-23
PhenytoinLevetiracetamPlacebo
Epilepsy

Pharmacogenetics-Based Study on Individualized Use of Sodium Valproate

RECRUITING
NCT07046676Phase PHASE4The First Affiliated Hospital of University of South ChinaStarted 2022-12-01
sodium valproate
Post-ERCP Acute Pancreatitis

An European Multi-centre Cohort Study for Unravelling Pharmacokinetic and Genetic Factors Underlying Post-ERCP Pancreatitis

RECRUITING
NCT05267379Radboud University Medical CenterStarted 2022-03-01
Take blood samples
Epilepsy

Precision Medicine in the Treatment of Epilepsy

RECRUITING
NCT05450822Gitte Moos KnudsenStarted 2022-02-18
LevetiracetamLevetiracetam TabletsLamotrigine tablet
Obstructive Hypertrophic Cardiomyopathy (oHCM)

Biological Collection for the Purpose of Exploring Genetic and Clinical-biological Factors Associated With Variability in Response to Mavacamten in the Treatment of Obstructive Hypertrophic Cardiomyopathy

NOT YET RECRUITING
NCT07439952Assistance Publique - Hôpitaux de ParisStarted 2026-02-05
THC

THC Titration of High-Potency Cannabis Concentrates

RECRUITING
NCT07105449Phase NACentre for Addiction and Mental HealthStarted 2025-10-01
Cannabis (30% THC Concentrate)Cannabis (60% THC Concentrate)Cannabis (90% THC Concentrate)
Risk FactorsPolypharmacyDrug Interactions

Telecommunication Technology-based Online Survey

RECRUITING
NCT06159699Tomsk National Research Medical Center of the Russian Academy of SciencesStarted 2022-12-02
Online SurveyGenetic Testing
Atrial Fibrillation

REGistry of Long-term AnTithrombotic TherApy-2

RECRUITING
NCT04347187National Medical Research Center for Cardiology, Ministry of Health of Russian FederationStarted 2015-01-15
Anticoagulants