Mental health and behavioural problems in children with XXYY: a comparison with intellectual disabilities

Background\ud \ud The phenotype of children with XXYY has predominantly been defined by comparison to other sex chromosome aneuploidies trisomies affecting male children; however, the intellectual ability of children with XXYY is lower than children with other sex chromosome aneuploidies trisomies. It is not known to what extent the phenotype identified to date is specific to XXYY, rather than a reflection of lower IQ. This study evaluates the mental health and behaviour of children with XXYY, in comparison to children with intellectual disabilities of heterogeneous genetic origin.\ud \ud \ud Methods\ud \ud Fifteen children with XXYY and 30 controls matched for age (4–14 years), sex and intellectual ability were ascertained from the IMAGINE ID study. IMAGINE ID participants have intellectual disabilities due to genetic anomalies confirmed by National Health Service Regional Genetic Centre laboratories. The mental health and behaviour of participants was examined with the Development and Well‐being Assessment and the Strengths and Difficulties Questionnaire.\ud \ud \ud Results\ud \ud Children with XXYY experienced significantly more frequent and intense temper outbursts than the control group.\ud \ud \ud Conclusion\ud \ud Our results suggest that temper outbursts may be specifically associated with the XXYY phenotype. These problems have a significant impact on the daily lives of boys with XXYY and their families. It is crucial to ensure that families are well supported to manage these difficulties.