Transient visual evoked potential abnormalities in ADNP syndrome

ADNP syndrome is a rare genetic disorder associated with global developmental delay/intellectual disability, autism, aberrant behavior, and medical comorbidities. Sensory symptoms represent a core clinical feature, even in those without autism spectrum disorder (ASD). Differences in visual evoked potentials (VEPs), an objective measure of excitatory and inhibitory postsynaptic activity, have been reported in other genetic neurodevelopmental disorders and have yet to be examined in ADNP syndrome. Transient VEPs (tVEP) were collected from 12 children with ADNP syndrome, 46 autistic children without a known genetic cause, and 19 typically developing children. Time- and frequency-domain variables were compared between groups. Significant differences were found between the ADNP and TD groups in amplitude (P60-N75, N75-P100), latency (P60, N75), and magnitude-squared coherence (MSC). Significant differences were also found between the ADNP and ASD group in latency (P60, N75) and MSC (Band 2, 14–28 Hz). VEP abnormalities in children with ADNP syndrome compared to an ASD group and controls were identified. Weaker amplitudes in the ADNP group are consistent with prior research in other genetic neurodevelopmental syndromes. Longer latencies and diminished 14–28 Hz band activity, however, are distinct findings and represent an important area of continued study to explore the presence of syndrome-specific VEP profiles. Establishing VEP biomarkers for ADNP syndrome is a critical direction for future clinical trials in the syndrome.