NUDT15 genotyping

Diagnostic Use

NUDT15, along with TPMT, is an enzyme involved in the metabolism of thiopurines. Thiopurines (azathioprine, mercaptopurine and thioguanine) are used clinically in the treatment of both malignant and non-malignant disorders. Variants in both NUDT15 and TPMT can result in pronounced pharmacologic effect of thiopurines and toxicity, as well as predispose to myelosuppression. Due to this, NUDT15 and TPMT genotyping is recommended prior to commencement of treatment, in order to inform starting doses of thiopurines according to the CPIC guidelines (Relling MV et al. 2019). While inherited TPMT deficiency is the primary genetic cause of thiopurine intolerance in Europeans and Africans, NUDT15 risk alleles explain the majority of thiopurine-related myelosuppression in Asians and Hispanics.

The variant NUDT15:c.415C>T is common to the NUDT15*2 and NUDT15*3 alleles ([c.38_43GAGTCG;c.415C>T] and c.415C>T respectively). The *2 and *3 variants account for >98% of the NUDT15 variant alleles leading to low enzyme activity in the general population, they are more common in Asian populations.


Genetics - Molecular Pathology

Delphic Registration Code



Thiopurine metabolism

Turnaround Time

14 days