CDKL5 and ethylmalonic encephalopathy: Using targeted gene sequencing, Na et al. (12) recently identified pathological variants in 42.9% (30/70) of infants with neonatal-onset EE, with the most common pathogenic variants detected in the KCNQ2, STXBP1, and CDKL5 genes (20/30, 66.7%).