CDKL5 and infantile epileptic encephalopathy: WES revealed variations in the two genes, CDKL5 and KCNQ2. The variation in CDKL5 was a de novo hemizygous mutation in (c.119C > T, p.Ala40Val), which has been previously reported to be responsible for early infantile epileptic encephalopathy (Rosas-Vargas et al., 2008).