In fact, individuals with mild/moderate ID have been described in BFNE pedigrees (I317T, R330L; Soldovieri et al., 2014; Miceli et al., 2015); moreover, de novo variants in KCNQ3 have been described in children with DEE (Allen et al., 2013; Grozeva et al., 2015; Miceli et al., 2015; Ambrosino et al., 2018; Lauritano et al., 2019), ID apparently without epilepsy (Rauch et al., 2012; Deciphering Developmental Disorders, 2017), cortical visual impairment (Bosch et al., 2016), and in patients with ID and autism (Sands et al., 2019). Here, KCNQ3 is linked to Cerebral visual impairment.