About 1 in 650-1000 children are born with a 47,XXY, 47,XXX or 47,XYY chromosomal pattern (i.e, sex chromosome trisomies, SCT). The presence of SCT is associated with an increased risk for... Show moreAbout 1 in 650-1000 children are born with a 47,XXY, 47,XXX or 47,XYY chromosomal pattern (i.e, sex chromosome trisomies, SCT). The presence of SCT is associated with an increased risk for neurodevelopmental difficulties across the life-span. Studying neurodevelopment in early childhood in children with SCT could signal deviations in development that serve as risk markers to guide clinical care. This thesis explored the development of self-regulation (emotion, cognition, and behavior) in SCT children and population-based controls, aged 1 to 7 years, who participated in the TRIXY Early Childhood Study. Behavioral symptoms were assessed through structured behavioral observation and parental questionnaires. Neurocognition was measured using performance tests and psychophysiological measures of arousal. Outcomes showed behavioral symptoms of psychopathology and neurocognitive vulnerabilities, already from an early age. Difficulties in self-regulation tended to become more pronounced with increasing age and were rather robust; independent of karyotype, pre/postnatal diagnosis, or intelligence-levels. A developmental neurocognitive perspective is key in increasing our knowledge of gene-brain-behavior pathways in SCT as well as advancing clinical care (diagnostics and treatment). Self-regulation amongst other neurocognitive functions may serve as a valuable target for early, tailor-made interventions to minimize the risk for psychopathology later in life and improving quality of life. Show less
