Mutations in voltage-gated potassium channel KCNC3 cause degenerative and developmental central nervous system phenotypes

Nat Genet. 2006 Apr;38(4):447-51. doi: 10.1038/ng1758. Epub 2006 Feb 26.


Potassium channel mutations have been described in episodic neurological diseases. We report that K+ channel mutations cause disease phenotypes with neurodevelopmental and neurodegenerative features. In a Filipino adult-onset ataxia pedigree, the causative gene maps to 19q13, overlapping the SCA13 disease locus described in a French pedigree with childhood-onset ataxia and cognitive delay. This region contains KCNC3 (also known as Kv3.3), encoding a voltage-gated Shaw channel with enriched cerebellar expression. Sequencing revealed two missense mutations, both of which alter KCNC3 function in Xenopus laevis expression systems. KCNC3(R420H), located in the voltage-sensing domain, had no channel activity when expressed alone and had a dominant-negative effect when co-expressed with the wild-type channel. KCNC3(F448L) shifted the activation curve in the negative direction and slowed channel closing. Thus, KCNC3(R420H) and KCNC3(F448L) are expected to change the output characteristics of fast-spiking cerebellar neurons, in which KCNC channels confer capacity for high-frequency firing. Our results establish a role for KCNC3 in phenotypes ranging from developmental disorders to adult-onset neurodegeneration and suggest voltage-gated K+ channels as candidates for additional neurodegenerative diseases.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cerebellar Ataxia / genetics*
  • Humans
  • Ion Channel Gating*
  • Molecular Sequence Data
  • Mutation*
  • Mutation, Missense*
  • Phenotype
  • Shaw Potassium Channels / chemistry
  • Shaw Potassium Channels / genetics*
  • Xenopus laevis


  • KCNC3 protein, human
  • Shaw Potassium Channels

Associated data

  • RefSeq/NM_004977