Genetic insight into cytochrome P450 in Chinese from the Chinese Millionome Database

Genetic variations of cytochrome P450 (CYP) influence the inter-individual differences in drug response. Here, we collected 8682 variants of 57 CYP genes and cytochrome P450 oxidoreductase (POR) from a large-scale sequencing project in Chinese, Chinese Millionome Database (CMDB). In addition, 52 294 variants from the Genome Aggregation Database (gnomAD) had been simultaneously identified and analysed. Rare variants with a variant allele frequency (VAF) < 0.01 comprised 41.4% (3594/8682) of identified variations in the CMDB, while 98.1% (51 320/52 294) in the gnomAD were rare. Out of 8682 variants in the CMDB, 66.9% (5808/8682) were in introns and only 4.3% (377/8682) were missense variants. In contrast, 36.2% (18 929/52 294) variants in the gnomAD were missense. The common alleles with a VAF over 0.1 were found in CYP1A2*1C, CYP1A2*1F, CYP2C19*2, CYP2D6*2, CYP2D6*10, CYP3A5*3 and CYP4F2*3, with a VAF of 0.161, 0.6, 0.27, 0.274, 0.678, 0.92 and 0.233, respectively. The growing number of genetic variations in CYP genes as more genomes are sequenced would increase the power to predict drug metabolism and response based on the genotype of the particular individual.