Classic pharmacogenetic traits: the thiopurine S-methyltransferase polymorphism

(A) Cytochrome P450 2D6 (CYP2D6) pharmacogenetics determined using the ratio of debrisoquine to its metabolite, 4-hydroxydebrisoquine, in 1,011 Swedish subjects. This population sample included a group of 'poor metabolizers' (PMs), a large group of 'extensive metabolizers' (EMs) and a small number of 'ultra-rapid metabolizers' (UMs). The box labelled 'cut off' indicates the cut off between data for subjects with 'poor' metabolism as a result of decreased or absent CYP2D6 activity and subjects with 'extensive' metabolism. (B) Roche AmpliChip P450 Array. The photograph shows a device that can be used to determine genotypes for alleles of selected CYP genes, including CYP2D6.