NAT2*75 is assigned decreased function based on moderate evidence. NAT2*75 is defined by the core SNVs c.264G>A (p.M88I) and c.341T>C (p.I114T). c.341T>C (p.I114T) defines NAT2*5 which has been extensively studied, exhibiting decreased N-acetyltransferase activity both in vivo and in vitro. In vitro studies also show that NAT2*5 (which contains the core SNV c.341T>C, p.I114T) is subjected to enhanced protein degradation by the proteasome (15564878). Thus, NAT2*75 would presumably be degraded in the same manner. Additionally, five out of ten variant effect predictors tested by CPIC staff predict that c.341T>C (p.I114T) impairs protein function. There is no literature describing function for c.264G>A. Ten out of ten variant effect predictors tested by CPIC staff predict that c.264G>A (p.M88I) is neutral for protein function. NAT2*75 is assigned decreased function based on c.341T>C. Despite this, the combinatorial effects associated with c.341T>C and c.264G>A are uncertain.