NAT2*42 is assigned uncertain function based on inadequate evidence. NAT2*42 is characterized by the core SNV c.622T>C (p.Y208H). Published in silico modeling predicts that c.622T>C (p.Y208H) does not alter NAT2 protein function (19909761). Four out of nine variant effect predictors tested by CPIC staff predict that c.622T>C (p.Y208H) impairs protein function. There are no in vitro or in vivo functional studies for NAT2*42