Hypothesizing that KCNN3 genotypes do not influence susceptibility to schizophrenia but modify its phenotype, we explored their contribution to specific schizophrenic symptoms.
In the present study, we chose three potassium channel genes, KCNH1, KCNJ10, KCNN3 to investigate the role of potassium channels in schizophrenia by genotyping 23 SNPs (9 in KCNH1, 5 in KCNJ10 and 9 in KCNN3) in a Han Chinese sample consisting of 893 schizophrenia patients and 611 healthy controls.
The small-conductance calcium-activated K(+) channel SK3 (SKCa3/KCNN3) regulates electrical excitability and neurotransmitter release in monoaminergic neurons, and has been implicated in schizophrenia, ataxia and anorexia nervosa.
Initial evidence for association of both schizophrenia and bipolar disorder with increased CAG-repeat length of KCNN3 has not been consistently replicated.
Recently, a 4-base pair deletion in SKCa3 was reported in a patient with schizophrenia, which truncates the protein at the end of the N-terminal cytoplasmic region (SKCa3Delta).
A recent report has implicated a potassium channel-coding gene, KCNN3, which contains a polymorphic CAG repeat in its coding region, in schizophrenia and bipolar disorder.
hKCa3/KCNN3 potassium channel gene: association of longer CAG repeats with schizophrenia in Israeli Ashkenazi Jews, expression in human tissues and localization to chromosome 1q21.
Polymorphic polyglutamine tracts are present in a recently described human, calcium-activated potassium channel, KCNN3 (also known as hKCa3), and alleles of this gene that contain longer repeats have been associated with schizophrenia.