Rare variants in proximity to V1686M in CaV2.1 have previously been associated with episodic ataxia type 2, familial hemiplegic migraine and spinocerebellar ataxia type 6, demonstrating the importance of the P/Q type current for the nervous system (Ducros et al., 2001). The gene discussed is CACNA1A; the disease is episodic ataxia type 2.