A – 68 Rare Pediatric Neurodevelopmental Disorders: A Neuropsychological Sampler

Abstract Objective This review provides a comprehensive neurocognitive and behavioral profile of rare pediatric neurodevelopmental disorders, focusing on their neurological, cognitive, behavioral, social-communicative, and psychological manifestations to inform neuropsychological assessment and intervention approaches. Method Literature was identified through searches of neurogenetic and neurodevelopmental databases, focusing on disorders with prevalence rates below 1:10,000. Selected disorders were categorized into three major groupings: neurocutaneous syndromes, microdeletion syndromes, and genomic imprinting disorders, with additional coverage of regression syndromes. Each condition was evaluated across six functional domains: neurological, biological/genetic, cognitive, behavioral, social/communicative, and psychological/emotional. Results Analysis reveals distinctive neuropsychological profiles across disorders despite some shared features. Neurocutaneous disorders (Tuberous Sclerosis Complex, Neurofibromatosis Type 1) feature tumor growth affecting neural functioning with variable cognitive impacts. Microdeletion syndromes (Williams Syndrome, 22q11.2 Deletion Syndrome, Smith-Magenis Syndrome) demonstrate unique cognitive-behavioral signatures, from the hypersociability and visuospatial deficits in Williams Syndrome to the psychosis risk in 22q11.2 Deletion Syndrome. Genomic imprinting disorders (Angelman Syndrome, Prader-Willi Syndrome) show opposing phenotypes despite involving the same chromosomal region. Regression syndromes (Rett Syndrome, Landau-Kleffner Syndrome) feature characteristic developmental regression patterns affecting language and motor skills. Conclusion These rare disorders present distinct neuropsychological profiles requiring specialized assessment and intervention approaches. Common themes include executive functioning challenges, social-communication difficulties, and heightened risk for behavioral/emotional problems, though the specific manifestations vary significantly across conditions. Neuropsychological evaluation of these populations should incorporate knowledge of syndrome-specific strengths and weaknesses, with intervention plans targeting each child's unique neurocognitive profile rather than diagnostic label alone.