NAT2*50 is assigned decreased function based on moderate evidence. NAT2*50 is characterized by the core SNVs c.7A>G (p.I3V), c.590G>A (p.R197Q), and c.803G>A (p.R268K). c.803G>A (p.R268K) defines NAT2*4, formerly considered the reference allele, which has repeatedly shown increased function in vivo and in vitro. There is no literature supporting a function for c.7A>G (p.I3V). One out of ten variant effect predictors tested by CPIC staff predicts that c.7A>G (p.I3V) impairs protein function. c.590G>A (p.R197Q) defines NAT2*6 which has repeatedly shown decreased N-acetyltransferase activity in numerous in vivo and in vitro studies. Similarly, seven out of ten variant effect predictors tested by CPIC staff predict that c.590G>A (p.R197Q) impairs protein function. Thus, NAT2*50 is assigned decreased function based on c.590G>A. While c.7A>G is not predicted to impair protein function, the combinatorial effects associated with c.590G>A and c.7A>G are uncertain.