Nudix Hydrolase 15
NUDT15 protects cells from thiopurine chemotherapy by breaking down active thioguanine nucleotides before they cause too much damage. Loss-of-function NUDT15 variants are common in East Asian and Hispanic populations and cause severe bone marrow suppression on standard thiopurine doses. NUDT15 testing is now considered as essential as TPMT testing before starting azathioprine, mercaptopurine, or thioguanine.
Gene2Rx reports your NUDT15 genotype across 19 named star alleles, built from 17 variants curated by PharmVar.
Star alleles (like *1, *2, *4) are standardized names for distinct versions of a pharmacogene. *1 is the reference; higher numbers identify variants discovered later that change the enzyme's activity.
You inherit one allele from each parent, so your genotype is a pair (e.g. *1/*4). The pair determines your predicted phenotype — for example, whether you metabolize a drug at a normal, decreased, or no-function rate.
PharmVar is the international registry that defines and curates these allele names. Gene2Rx tests the variants required to call every NUDT15 allele in the PharmVar catalog.
Gene2Rx covers 3 medications with published pharmacogenetic guidance for NUDT15, drawn from CPIC and FDA sources. Each drug links to its full pharmacogenetics page.
These branded medications include at least one active ingredient whose metabolism or action involves NUDT15. Each links to its full pharmacogenetic breakdown.
This page lists drugs affected by NUDT15. A Gene2Rx report tells you which metabolizer group you fall into, and what that means for every medication on this list.
Get your report Look up a medicationInformational only, not medical advice. The presence of a NUDT15 pharmacogenetic guideline does not mean every patient needs to change their dose. Never start, stop, or change a medication without talking to your prescribing clinician.