Coffin-Siris syndrome (CSS) is a rare genetic disorder presenting physical abnormalities and cognitive developmental challenges. Research into cognitive and developmental aspects of CSS could shed...Show moreCoffin-Siris syndrome (CSS) is a rare genetic disorder presenting physical abnormalities and cognitive developmental challenges. Research into cognitive and developmental aspects of CSS could shed light on the development of emotional and behavioural problems which could contribute to early detection and preventive measures. This study investigates core executive functions (Behaviour Rating Inventory of Executive Functions) and emotional and behavioural problems (Child Behavioural Checklist) in 15 CSS children aged 3-18 years. Core executive functions are compared between 12 children with CSS children and 26 TD children matched on mental age. Additionally, this study delves into the relationship between core executive functions and emotional and behavioural problems. Children with CSS exhibited attention deficit/hyperactivity, anxiety and oppositional defiant problems. The majority of children with CSS also exhibited problems in cognitive flexibility and working memory. However, inhibition problems were in line with TD children. Children with CSS displayed equal levels of inhibition and working memory problems compared to their peers with a similar developmental level but showed increased levels of cognitive flexibility problems. Findings suggest that there is no correlation between total executive functioning and emotional and behavioural problems in children with CSS. However, a relationship was found between inhibition and overall emotional and behavioural problems, and specifically attention deficit/hyperactivity. Additional investigations are necessary to conduct comprehensive assessments of executive functions in children with CSS, particularly considering their intellectual development. Additionally, recommendations for future research are provided to further explore the connection between executive functions and emotional and behavioural problems in children with CSS. These findings provide first insight into executive functions in children with CSS and their relationship with emotional and behavioural problems. These findings may aid the development of tailored interventions aimed at improving adaptive functioning, reduce emotional and behavioural problems, and enhance quality of life.Show less