Prevalence of CYP2C19 polymorphism in Bogotá, Colombia: The first report of allele *17

Proton pump inhibitors (PPIs) are a group of drugs that are essential for the treatment of acid-related disorders, such as gastroesophageal reflux (GERD), dyspepsia, gastric ulcers and Helicobacter pylori (H. pylori) infection. PPIs such as omeprazole, esomeprazole, pantoprazole and lansoprazole are metabolized by the CYP2C19 enzyme, which is encoded by a polymorphic gene. Four polymorphisms have an impact on the speed of PPI metabolism: CYP2C19*1/*1 (extensive metabolizers), CYP2C19*2/*2 (intermediate metabolizers), CYP2C19*3/*3 (poor metabolizers) and CYP2C19*17/*17 (ultrarapid metabolizers). Extensive and ultrarapid metabolizers inactivate PPIs quickly, which consequently causes low plasma concentrations of PPIs, while intermediate or poor metabolizers have higher plasma concentrations of PPIs and, therefore, PPIs have greater therapeutic efficacy in individuals with these polymorphisms.

To determine the frequency of genetic polymorphisms of the CPY2C19 enzyme in Bogotá, Colombia.

This observational study was conducted in Bogotá between 2012 and 2015 and was part of a clinical trial (ID: NCT03650543). It included 239 subjects with dyspepsia, H. pylori infection, or GERD symptoms. CYP2C19 genotyping was performed on gastric biopsy samples. Polymorphisms *1, *2, and *3 were analyzed by real-time PCR (Roche®), and PCR-RFLP was used to determine the presence of polymorphism *17.

The distribution of different types of PPI metabolizers was as follows: extensive (70.7%), ultrarapid (12.9%), intermediate (8.8%) and poor (0.8%).

The population studied consisted mainly of extensive and ultrarapid PPI metabolizers. These findings show that it is necessary to increase PPI doses in this group of subjects or to use PPIs that are not metabolized by CYP2C19 (rabeprazole). This is the first Colombian work to identify ultrarapid metabolizers.