STX1A and Progressive cerebellar ataxia: Episodic Ataxia 2 (Cricchi et al., 2007; Serra et al., 2010) is a rare disorder with an early onset characterized by progressive ataxia and one of the P/Q-channel mutations associated with EA2 is A454T, which was shown to have stronger inactivation coupled with a reduced modulation by Syntaxin 1A and SNAP-25, which reduced exocytosis (Serra et al., 2010).