KCNC3 and spinocerebellar ataxia type 13: Most importantly, we identified a variant in the SCA13-associated gene KCNC3, encoding the voltage-gated Kv3.3 channel, with a c.2023G > A nucleotide exchange, that causes a charge reversing p.Glu675Lys amino acid exchange of a highly conserved amino acid in the cytosolic C-terminus of the channel protein (Figures 1C,D).