Psychological functioning, brain morphology, and functional neuroimaging in Klinefelter syndrome

Klinefelter syndrome (KS; 47,XXY) impacts neurodevelopment and is associated with an increased risk of cognitive, psychological and social impairments, although significant heterogeneity in the neurodevelopmental profile is seen. KS is characterized by a specific cognitive profile with predominantly verbal deficits, preserved function in non-verbal and visuo-spatial domains, executive dysfunction and social impairments, and by an increased vulnerability toward psychiatric disorders. The neurobiological underpinnings of the observed neuropsychological profile have not been established. A distinct pattern of both global and regional brain volumetric differences has been demonstrated in addition to preliminary findings of functional brain alterations related to auditory, motor, language and social processing. When present, the combination of cognitive, psychological and social challenges has the potential to negatively affect quality of life. This review intends to provide information and insight to the neuropsychological outcome and brain correlates of KS. Possible clinical intervention and future directions of research will be discussed.