NUDT15*13 is assigned no function based on limited evidence. The NUDT15*13 SNV (NM_018283.4:c.343dup) results in a frameshift at amino acid residue 115 and the loss of the enzymatic domain (29519865). Patients carrying a NUDT15*13 allele had a 33% reduction in thiopurine dosage following the occurrence of adverse reactions (29519865). NUDT15*13 is characterized by the duplication c.343_344insG (p.E115fs), which is predicted to impair protein function by CADD and Phd-SNPg