A – 55 Neurodevelopmental Profile in Babies and Preschoolers with Kabuki Syndrome

Abstract Objective This study aims to explore the KS baby and preschooler cognitive-behavioral profile. Kabuki syndrome (KS) is a genetic disorder caused by pathogenic variants in KMT2D or KDM6A. The KS cognitive-behavioral profile has only been described in older individuals and is characterized by mild intellectual disability (ID) with specific weaknesses in visuospatial and motor skills with strengths in language, and difficulties in adaptive skills and executive functioning. Method Twenty-two babies and preschoolers (Mage=38.95 months, 11-70 months, 68% female) with confirmed KS variants participated in research at an academic hospital. Behaviors were measured by the Child-Behavior Checklist, Adaptive Behavior Assessment System-3 (ABAS-3), and Behavior Rating Inventory of Executive Functioning (BRIEF). Cognitive functioning was assessed with the Bayley-4 for participants under thirty-five months, and Weschler Preschool and Primary Scale of Intelligence (WPPSI) over thirty-six months. Visuospatial abilities were measured by the Beery Visuomotor Integration Test for preschoolers only. Results Participants had little to no behavior problems (M=56.39, SD=10.44), but difficulties in adaptive skills (M=72.69, SD=16.23). Preschoolers had high levels of executive dysfunction (M=69.18, SD=14.29). Most babies and preschoolers scored in mild ID (45%). 90% of babies had significant difficulties in motor skills (M=61.1, SD=15.25). Babies and toddlers scored higher in language skills (M=71.15, SD=16.47) than visuospatial skills (M=65.22, SD=16.39). Conclusion The cognitive profile seen in KS babies and preschoolers is similar to older KS individuals with strengths in language and difficulties in visuospatial and motor skills. Babies and preschoolers with KS have low behavior problems like older individuals, but this group has high rates of executive dysfunction.