The study of Splawski et al. [42] described the phenotypic characterization of Timothy syndrome (TS) and identified two analogous mutations, p.G406R and p.G402S in CACNA1C, which led to significantly impaired current inactivation of the Cav1.2 splice form, raised the possibility that the ASD phenotypes associated with TS may result from the CACNA1C gain-of-function mutation. The gene discussed is CACNA1C; the disease is Timothy syndrome.