KCNQ2 and epilepsy: The observation that epilepsy-associated variants in KCNQ2 are more than 10 times more frequent than those in KCNQ3, suggests that KCNQ3 tolerates variation better than KCNQ2. Several pieces of evidence support this view; as an example, while heterozygous frameshift variants in KCNQ2 are frequent causes of BFNE (Miceli et al., 2018), no heterozygous pathogenic frameshift KCNQ3 variant has ever been associated with a human phenotype.