CACNA1C and Timothy syndrome: Interestingly, the positions of G403R and G403D (exon 8) and G407R (exon 8a) are identical to the Timothy syndrome mutations G402 and G406 (see above) in CACNA1C and also cause very similar gating defects (type 1; Scholl et al., 2013; Pinggera et al., 2018).