Fig. 1

Visual Evoked Potentials. A Grand average VEP waveforms for TD, RTT, CDD, MDS, and FOXG1 groups at electrode Oz. B Box plots showing the distribution of the latency and amplitude of the VEP components for TD, RTT, CDD, MDS, and FOXG1 participants. The amplitude of multiple components was reduced in RTT, CDD, and MDS groups compared to the TD group. Statistical analyses were performed with Kruskal–Wallis tests and post-hoc tests analyses with Bonferroni-adjusted p values for significance (*p < 0.005). C Scatterplots showing the association between VEP N1-P1 amplitude and clinical severity (CSS and MBA) for RTT, CDD, MDS, and FOXG1 participants. N1-P1 amplitude was significantly associated with both severity measures in participants with RTT and FOXG1. No aspects of the VEP were significantly associated with severity for the other groups. Statistical analyses were performed using linear regression (*p < 0.05)