PCR direct sequencing was used to analyse CACNA2D2 G>A (rs5030977) and ABCB1 C3435T (rs1045642) SNP genotypes. Briefly, the PCR-product was mixed with Exo-SAP-IT (USB, Cleveland, OH, USA), diluted 1:20 with H2O and incubated in 37°C, 30 min. Exo-SAP-IT was inactivated by heating at 80°C for 20 min. Direct DNA sequencing were performed at Macrogen (Seoul, Korea).
