Abstract

Background: Pharmacogenetics is at the heart of precision medicine. The CYP2C19 gene encodes the cytochrome P450 2C19 enzyme which is involved in the metabolism of proton pumps inhibitors in liver. The most common alelles encoding non-functional proteins are CYP2C19*2 and CYP2C19*3. Objectives: (1) Establish a process to identify CYP2C19*2 and *3 polymorphisms by PCR-RFLP technique; (2) Determine the prevalence of CYP2C19 genotypes by *2 and *3 polymorphisms among H. pylori-positive patients with gastroduodenal diseases. Materials and methods: DNA samples were extracted from 112 gastric biopsy specimens. The CYP2C19*2 and *3 polymorphisms were identified by PCR-RFLP technique. Confirming the results in 10% of the samples randomly by Sanger sequencing. Results: The PCR-RFLP results of validated samples were in 100% concordance with sequencing results. The frequencies of the *1, *2 and *3 alleles of the CYP2C19 gene were 67.9%, 29% and 3.1%, respectively. The proportion of groups with normal metabolizer, intermediate metabolizer and poor metabolizer genotypes were 45.5%, 44.7% and 9.8%, respectively. Conclusion: The intermediate/poor metabolizer genotype accounted for a high rate. PCR-RFLP is an accurate and cost-effective method to determine CYP2C19*2 and CYP2C19*3 polymorphisms. This technique can be applied to identify polymorphisms in patients with gastroduodenal disorders as a guidance for personalized therapy.