Interestingly, one had epilepsy with abnormal EEG due to a heterozygous 670 kb deletion of chromosome 12q21 that covers full-length ATXN7L3B and 3–5 exons of KCNC2. Consistently, our findings in two unrelated patients have supported the theory that KCNC2 is a DEE causative gene. The gene discussed is KCNC2; the disease is epilepsy.