SLC22A2 and atrial fibrillation: Therefore, the observed variants on the SLC22A1 gene (rs2282143 with AF of 10.8%) and the SLC22A2 gene (rs316019 with AF of 85.3%) can disrupt the transportation of many drugs (such as flurazepam, antihistamines of the first generation, metoprolol, propranolol, ...).