Growing up with X and Y chromosome trisomy: the TRIXY study

Approximately 1 to 2 in 1000 children have an extra X or Y chromosome, also
referred to as *sex chromosome trisomies* (SCT). Considering the high
prevalence of SCT and the exceptional high density of genes on the sex
chromosomes that are essential for brain development, children with SCT are at
increased risk for neurodevelopmental problems. However, the number of studies
on SCT is limited and the vast majority of publications (75 %) are focused on
physical problems. Also, there are no evidence based psychosocial interventions
available for these populations. This study will provide in this. Knowledge on
psychological, i.e. neurodevelopmental, risks and opportunities to positively
influence development in SCT is needed to A) learn about early risk factors in
development, that can serve as markers for monitoring vulnerable children B)
improve clinical care, which will become even more important with the expected
increase in the number of identified cases with the new Non-Invasive Prenatal
Test that has been introduced in 2014.

The aims of this study are to
1) To identify information processing deficits that can help explain predict
communication impairments, language deficits, social problems and increased
risk for psychopathology.
2) To assess if lack of regulation of emotional arousal (expressed in heart
rate and skin conductance) is underlying communication impairments, language
deficits, social problems and increased risk for psychopathology in children
with SCT. We will also assess to what degree cognitive impairments (in areas of
social cognition, language and executive functioning) are associated with
emotion regulation problems.
3) To evaluate effectiveness of cognitive-behavioral, parent mediated
intervention tools targeted at stimulating social-emotional development

This is a longitudinal study, including case-control observations and
psychosocial intervention.

Psychosocial intervention will include parent mediated intervention tools
targeted at stimulating social-emotional development. Assignment is
semi-random.

There are no risks involved. The burden includes time investment, with a
maximum of 90 minutes per visit for toddlers and a maximum of 120 minutes per
visit for preschooler. Time investment for parents is 4 hours, for interviews
and questionnaires. Child assessments include behavior observations,
neuropsychological tests, eyetracking, and arousal measures (heart-rate and
skin conductance). All paradigms are developed for young children and
administered by an experimenter trained in assessments with young children. All
3 to 6 year old participants in the clinical group participate in intervention,
which involves comparing various types of psychosocial support.