KCNQ2 and developmental and epileptic encephalopathy: Zou et al found that the most common epilepsy-related duplication copy number variations were 17p13.3, 16p11.2, and 7q11.23.[38] Nappi et al found that mutations in KCNQ2, KCNQ3, and KCNQ5 were associated with DEE.[39]