Assessment of Adaptive Functioning and the Impact of Seizures in KBG Syndrome

This study aimed to examine the adaptive functioning status and the impact of epileptic seizures on neurocognitive outcomes in KBG syndrome, a rare genetic neurodevelopmental disorder characterized by pathogenic variants in ANKRD11. A single clinician interviewed individuals and families with genetically confirmed cases of KBG syndrome. Trained professionals also conducted assessments using the Vineland-3 Adaptive Behavior Scales. The assessment covered the domains of communication, daily living skills, socialization, and maladaptive behaviors, and then compared individuals with and without epilepsy. Further comparisons were made with data from interviews and participants' medical records. Thirty-nine individuals (22 males, 17 females) with KBG syndrome, confirmed through genetic analysis, were interviewed via videoconferencing, followed by Vineland-3 assessment by trained raters. Individuals with KBG syndrome came from 36 unique families spanning 11 countries. While the KBG cohort displayed lower overall adaptive behavior composite scores compared with the average population, several members displayed standard scores at or higher than average, as well as higher scores compared with those with the neurodevelopmental disorder Ogden syndrome. Within the KBG cohort, males consistently scored lower than females across all domains, but none of these categories reached statistical significance. While the group with epilepsy exhibited overall lower scores than the nonseizure group in every category, statistical significance was only reached in the written communication subdomain. Our research provides insights that can aid in epilepsy screening and inform assessment strategies for neurocognitive functioning in those with this condition. The cohort performed overall higher than expected, with outliers existing in both directions. Although our results suggest that seizures might influence the trajectory of KBG syndrome, the approaching but overall absence of statistical significance between study groups underscores the need for a more extensive cohort to discern subtle variations in functioning.