Fig. 1

Metabolic status in a predominantly Malay group of Malaysians, assigned according to the following phenotypic scheme [18]: Activity score >2.25, ultrarapid metabolizer; 1.25–2.25, normal metabolizer; >0 and <1.25, intermediate metabolizer; 0, poor metabolizer. Participants with unknown metabolic status harbored CYP2D6 alleles whose functional significance had not been confirmed. The CYP2D6 alleles were genotyped by nanopore sequencing (Oxford Nanopore Technologies, UK)