CNKSR2 and epilepsy: Herein, we report a patient with clinical symptoms including attention deficit, poor logical thinking ability, and an introverted personality (but without epilepsy or electroencephalogram changes) caused by an out-of-frame exon deletion due to a splicing variant of CNKSR2. This is the first reported case with a splice variant in CNKSR2, which could enhance our understanding of the genotypic and phenotypic spectra of CNSKR2 in patients with neurodevelopmental disorders.