Abstract:Objective To analyze polymorphisms of CYP2C19 gene in patients with digestive system diseases in Wuhan. Methods The 314 unrelated Han patients with digestive system diseases were chosen and tested for polymorphisms of CYP2C19 gene in our hospital from January 2016 to December 2017. Real-time fluorescence quantitative PCR was used to detect the genotypes of CYP2C19 which were related to the metabolism of proton pump inhibitors, and the metabolic phenotypes were judged according to the genotypes. The correlations of genetic polymorphisms of CYP2C19 with sex, age, clinical classification of digestive system diseases were analyzed. Results A total of 8 genotypes (CYP2C19 *1*17, *1*1, *1*2, *1*3, *2*17, *3*17, *2*2 and *2*3) and 4 metabolic phenotypes [UM (0.96%), EM (36.94%), IM (45.54%) and PM (16.56%)] were detected. The CYP2C19 genotypes in the patients with different sex, age or clinical types of digestive system diseases had no statistical differences (P > 0.05); the CYP2C19 metabolic phenotypes of the patients with different sex or clinical types of digestive system diseases had no statistical differences (P > 0.05), while there were statistical differences in metabolic phenotypes of CYP2C19 among the patients with different age (P < 0.05). Conclusions The CYP2C19 gene in patients with digestive system diseases in Wuhan has polymorphisms, the distribution of allele frequency and the metabolic phenotype of CYP2C19 gene is similar to that in Asians, but obviously different from that of people in other countries such as Europeans.