Victoria Leggett|Patricia A. Jacobs|Kate Nation|Gaia Scerif|Dorothy V. M. Bishop
Neurocognitive outcomes of individuals with a sex chromosome trisomy: XXX, XYY, or XXY: a systematic review*
University of Oxford|Southampton General Hospital|Salisbury District Hospital|Wessex Regional Genetics Laboratory|University of Oxford|University of Oxford|University of Oxford
aim review systematically neurodevelopmental characteristics individuals sex chromosome trisomies scts method bibliographic search identified englishlanguage articles scts focus studies unbiased clinical referral power least 069 detect effect size 10 results identified 35 articles five neonatally identified samples adequate power review additional 11 studies included cases identified reasons neurodevelopmental concerns individuals additional x chromosome mean iqs within broadly normal limits lower respective comparison groups verbal iq affected cognitive outcomes poorest females xxx males xyy normalrange iqs three sct groups xxx xxy xyy marked difficulties speech language motor skills educational achievement nevertheless adults scts lived independently less evidence available brain structure attention social psychiatric outcomes within group much variation interpretation individuals scts risk cognitive behavioural difficulties however evidence base slender research needed ascertain nature severity causes difficulties unselected samples