KCNQ2 and bipolar disorder: For example, KCNQ2 and KCNQ3 genes have been identified as putative risk factors for bipolar disorders [108,109], and in particular, specific KCNQ2 variants (with a shorter C-terminal) are associated with suppressed channel activity, concordant with an effect on neuronal hyperexcitability, characteristic of a manic state [110].