TPMT*29 is assigned no function based on limited evidence. The TPMT*29 -defining SNV, c.2T>C (p.M1T), is predicted to disrupt protein translation due to the loss of the canonical start codon, and there is no alternative start codon available. An individual genotyped TPMT*1/*29 was predicted to be an intermediate metabolizer (22447118). Five out of eight variant effect predictors tested by CPIC staff predict that c.2T>C (p.M1T) impairs protein function.