A meta-analysis of NUDT15 (30 studies) genetic polymorphism on thiopurine-induced myelosuppression in Asians, showed that among NUDT15 polymorphisms, NUDT15*3 specifically showed a significantly increased risk of early leukopenia (OR 15.31) and early neutropenia (OR 15.85) [22]. This evidence concerns the gene NUDT15 and Decreased total leukocyte count.