The genetic heterogeneity can lead to heterogeneous drug responses among individuals, such as less efficacy or unwanted side effects of drug therapy. Moreover, the ethnic/genetic diversity also affects the effective prescription. Here, we investigated the genetic diversity of 282 ADME genes in five northwestern Chinese minority populations which are all admixed people with ancestry contributions from both Eastern and Western Eurasian populations. We revealed that substantial allelic and haplotype differences exist at drug related genes between those minority ethnic groups and Han Chinese, which is likely to violate a single, unified standard of medication in China. (By Dr. Shuhua Xu, http://jmg.bmj.com/content/early/2014/07/29/jmedgenet-2014-102530 )