 EA5 patients have a cysteine to phenylalanine mutation at position 104.Thus results in channels with 30% greater current than wild-type.As this subunit is expressed in the cerebellum, it is assumed that such increased current results in neuronal hyperexcitability

Coding and noncoding variation of the human calcium-channel beta4-subunit gene CACNB4 in patients with idiopathic generalized epilepsy and episodic ataxia.