In 2012, some heterozygous pathogenic variants in KCNQ2 were surprisingly shown to result in DEE, with a developmental delay ranging from mild to profound, nowadays referred to as “KCNQ2-encephalopathy” (KCNQ2-E; Weckhuysen et al., 2012). The gene discussed is KCNQ2; the disease is developmental and epileptic encephalopathy.