NCIt definition : Human CYP2D6*20 allele is located in the vicinity of 22q13.1 and is approximately
4 kb in length. The CYP2D6*20 allele, a variant form of the CYP2D6 wild-type allele,
encodes cytochrome P450 2D6*20 protein. The CYP2D6*20 allele exhibits a single nucleotide
insertion (g.1973insG) that results in a frameshift during protein coding. This alteration
abolishes the enzymatic activity of the cytochrome P450 2D6*20 protein.;