CYP2D6*46 is assigned normal function based on limited evidence. Subjects carrying the CYP2D6*46 allele demonstrated similar dextromethorphan metabolism and tramadol pharmacokinetics compared to subjects with two functional alleles (15768052). An vitro study found CYP2D6*46 demonstrated similar activity compared to wildtype with dextromethorphan and bufuralol substrates (15768052). Although two in vitro study found CYP2D6*46 demonstrated decreased enzyme activity compared to wildtype with dextromethorphan, bufuralol, and primaquine substrates (24647041, 30366777) the experts did not find this result convincing as CYP2D6*46 demonstrated similar activity compared to wildtype in vivo and in vitro with the same substrates. Therefore, consensus among experts was normal function with an activity value of 1 based on limited evidence.