SDK2 and panic disorder: Otowa and colleagues conducted GWAS studies of panic disorder (PD) in the Japanese population and found seven SNPs that are significantly associated with PD, which are located in or adjacent to genes such as PKP1, PLEKHG1, TMEM16B, CALCOCO1, SDK2 and CLU (Otowa et al., 2009). However, two follow up studies from the same group failed to show any significant association between SNPs in TMEM16B and PD (Otowa et al., 2012; Otowa et al., 2010).