CYP2D6*6x2 is assigned no function based on limited evidence. CYP2D6*6 is defined by a single nucleotide deletion resulting in a frameshift and premature stop codon yielding a truncated and nonfunctional protein (7894499). Therefore, consensus among experts was no function with an activity value of 0 based on limited evidence as it was determined the phenotypes containing a duplication of this allele would be clinically similar to phenotypes comprising the nonduplicated allele.