CYP2D6*130 is assigned uncertain function due to inadequate literature describing function of this allele. One in vitro study demonstrated substantially decreased intrinsic clearance CLint (Vmax/Km) of 3.2% compared to *1 for tamoxifen N-desmethylation; no activity was detectable for dextromethorphan O-demethylation (32759992). Therefore, consensus among experts was uncertain function due to inadequate evidence.