Correction to CPIC Guideline for TPMT, NUDT15 and Thiopurines

A correction to Table 1 of the "Clinical Pharmacogenetics Implementation Consortium (CPIC) Guideline for Thiopurine Dosing Based on TPMT and NUDT15 Genotypes: 2025 Update" was published in Clinical Pharmacology and Therapeutics.

An individual carrying one no function allele plus one decreased function allele is an Intermediate Metabolizer (IM), not a Possible Intermediate Metabolizer as shown in the original table. The therapeutic recommendations for TPMT IMs and Possible IMs are the same. The downloadable TPMT Phenotype Table and TPMT Diplotype-Phenotype Table on ClinPGx and the CPIC DB have been updated accordingly.