Conversely, no significant association between LTG-induced SCAR and HLA-B∗15:02 was found when compared with the two control groups, nor did we find significant differences in the other HLA alleles between the LTG-induced SCAR group and the two control groups. Earlier studies on CBZ-induced SJS/TEN and the HLA-B∗15:02 allele reported no associations with the MPE group (Chung et al., 2004; Hung et al., 2006). The chemical structure of LTG includes aromatic rings similar to CBZ and shared a common risk allele causing SJS/TEN which similarities with other aromatic AEDs, namely PHT and OXC (Hung et al., 2010). Previous studies have found an association between LTG-induced SJS/TEN and HLA-B∗15:02 in Han Chinese (An et al., 2010; Hung et al., 2010), but other studies have found no association in Japanese patients (Kaniwa et al., 2008) or European population (Alfirevic et al., 2006), due to the fact that the HLA-B∗15:02 allele is rare in the Japanese population (0.1%) and people of European descent (0%), according to data from Lee et al. (2010). However, data from all of these studies were limited due to the small sample sizes of LTG-induced SJS patients; therefore, association studies between the HLA genotype and LTG-induced SJS could not be performed.