Global distribution of CYP2C19 variants in clopidogrel-indicated populations: implications for pharmacogenomic-guided antiplatelet therapy

CYP2C19

Conversion of CYP2C19 diplotypes into metaboliser phenotypes, aggregated by world region in clopidogrel-indicated populations

This scoping review searched Scopus, PubMed, Ovid MEDLINE and Ovid Embase from inception to 6 July 2026 for studies reporting CYP2C19 diplotypes in clopidogrel-indicated populations. Forty-one studies totalling 18,958 participants were synthesised across Asia, the Middle East and North Africa, Europe and the Americas, then converted to phenotypes. Intermediate and poor metabolisers were most prevalent in East Asia (54.0-77.2%) and South Asia (47.3-71.1%), while rapid and ultrarapid metabolisers predominated in the Middle East and North Africa (27.3-44.3%) and Europe (27.3-36.2%). The most frequent diplotypes were *1/*2 among intermediate and *2/*2 among poor metabolisers.

Synthesis written by Geno'X. For the full original abstract, please refer to the source publication.

The contribution of this synthesis is not allele frequency, already well described, but its calculation restricted to populations actually eligible for clopidogrel, which reframes the expected yield of targeted genotyping. With more than one East Asian patient in two being an intermediate or poor metaboliser, the cost-benefit calculation of systematic testing differs by patient population. The authors themselves note that the observed distribution reflects general population trends: the review informs prioritisation, it brings no new drug response data.

Analysis by Dr Thibaut Benquey