ABSTRACT
This chapter presents the results of one such study that includes the largest number of 47,XYY children identified at birth. The literature relating to 47,XYY children changed its focus in 1968 from congenital malformation, to the association of tall stature and behavioural deviations as the indication for chromosome analysis. Multiple linear regression was used to fit a model to the various psychological measures on each control child, taking into account social class and mother’s educational level. During childhood, one 47,XYY boy sustained a fractured skull followed by meningitis and subsequently developed severe unilateral hearing loss. In early childhood, speech development was delayed more frequently for the cases than the controls. Behaviour in school was examined using the Bristol Social Adjustment Guide, completed by the teachers annually when the child was between the ages of 8 and 11 years. The 47,XYY boys as a group were reading in a manner expected for their level of cognitive ability and social class.
