NAT2*43 is assigned uncertain function based on inadequate evidence. NAT2*43 is characterized by the core SNV c.609G>T (p.E203D). Published in silico modeling predicts that c.609G>T (p.E203D) does not alter NAT2 protein function (19909761). Similarly, eight out of nine variant effect predictors tested by CPIC staff predict that c.609G>T (p.E203D) is neutral/tolerated for NAT2 protein function. The limited clinical data available for NAT2*43 was not sufficient to influence the allele clinical functional status.(24444407).