ABSTRACT
Arylamine N-acetyltransferase 2 has been related to drug side effects and cancer susceptibility; its protein structure and acetylation capacity results from the polymorphism's arrays on the NAT2 gene. Absorption, distribution, metabolism, and excretion, cornerstones of the pharmacological effects, have shown diversity patterns across populations, ethnic groups, and even interethnic variation. Although the 1000 Genomes Project database has portrayed the global diversity of the NAT2 polymorphisms, several populations and ethnicities remain underrepresented, limiting the comprehensive picture of its variation. The NAT2 clinical entails require a detailed landscape of its striking diversity. This systematic review spans the genetic and acetylation patterns from 164 articles from October 1992 to October 2020. Descriptive studies and controls from observational studies expanded the NAT2 diversity landscape. Our study included 243 different populations and 101 ethnic minorities, and, for the first time, we presented the global patterns in the Middle Eastern populations. Europeans, including its derived populations, and East Asians have been the most studied genetic backgrounds. Contrary to the popular perception, Africans, Latinos and Native Americans have been significantly represented in recent years. NAT2*4, *5B, and *6A were the most frequent haplotypes globally. Nonetheless, the distribution of *5B and *7B were less and more frequent in Asians, respectively. Regarding the acetylator status, East Asians and Native Americans harboured the highest frequencies of the fast phenotype, followed by South Europeans. Central Asia, the Middle East, and West European populations were the major carriers of the slow acetylator status. The detailed panorama presented herein, expands the knowledge about the diversity patterns to genetic and acetylation levels. These data could help clarify the controversial findings between acetylator states and the susceptibility to diseases and reinforce the utility of NAT2 in precision medicine.