rs12777823

This is a intergenic variant in the CYP2C18 gene.

Key Literature Trait Associations

Warfarin Dose (African American)

This intergenic variant in the CYP2C gene cluster significantly reduces warfarin dose requirements independently of CYP2C9 and VKORC1. The A allele is common in African Americans (~25%) and has been incorporated into the CPIC pharmacogenetics-guided warfarin dosing guideline for patients of African descent. Including rs12777823 improves warfarin dose prediction by 21% relative to algorithms that only consider CYP2C9 and VKORC1.

Perera MA et al. “Genetic variants associated with warfarin dose in African-American individuals: a genome-wide association study” Lancet (london, England) (2013)

Allele A

OR —

p 1.0e-15

Large GWAS

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GWAS Catalog Trait Associations (1)

Genome-wide significant associations (p < 5×10⁻⁸) from the NHGRI-EBI GWAS Catalog.

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ClinVar annotation

Drug Response★★★★

1 submitter6 publications

warfarin response - Dosage

View on ClinVar →

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Research that mentions this SNP (1)

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Association of Cytochrome P450 2C19 Genotype With the Antiplatelet Effect and Clinical Efficacy of Clopidogrel Therapy

AssociationN=656Shuldiner AR et al.(2009)· JAMA

This genome-wide association study identified the CYP2C19*2 loss-of-function variant (rs4244285) as a major determinant of clopidogrel response in 429 Amish individuals. The variant was associated with diminished platelet aggregation response to ADP stimulation (P=4.3×10⁻¹¹) and accounted for 12% of variation in clopidogrel response. In an independent cohort of 227 patients undergoing percutaneous coronary intervention, carriers of CYP2C19*2 had higher cardiovascular event rates (20.9% vs 10.0%, HR=2.42, P=.02).

Traits studied:Acute coronary syndromesCardiovascular ischemic eventsClopidogrel responsePercutaneous coronary intervention outcomesPlatelet aggregation