CHD2 and early-infantile DEE: In the CHD2 non-CNVs patients, both the myoclonic seizures (MS, 27.3%, 24/88) and generalized tonic-clonic seizures (GTCS, 19.3%, 17/88) were the top two types of the first seizures, which presented the difference than average value (5.87 people/seizure types).