However, the assessment of fine motor function in children with STXBP1 may be difficult due to the need to follow directions, which may be limited by language and cognitive deficits.41,42 As families of children with STXBP1 have reported difficulties with activities of daily living as a major concern,18 additional research to validate reliable fine motor function measures is necessary as potential treatments for STXBP1 are developed in the future. This evidence concerns the gene STXBP1 and Cognitive impairment.