Brain morphology in children with 47,XYY syndrome: a voxel- and surface-based morphometric study

The neurocognitive and behavioral profile of individuals with 47,XYY is increasingly documented; however, very little is known about the effect of a supernumerary Y-chromosome on brain development. Establishing the neural phenotype associated with 47,XYY may prove valuable in clarifying the role of Y-chromosome gene dosage effects, a potential factor in several neuropsychiatric disorders that show a prevalence bias towards males, including autism spectrum disorders. Here, we investigated brain structure in 10 young boys with 47,XYY and 10 age-matched healthy controls by combining voxel-based morphometry (VBM) and surface-based morphometry (SBM). VBM results show the existence of altered grey matter volume in the insular and parietal regions of 47,XYY relative to controls, changes that were paralleled by extensive modifications in white matter bilaterally in the frontal and superior parietal lobes. SBM analyses corroborated these findings and revealed the presence of abnormal surface area and cortical thinning in regions with abnormal grey matter and white matter volumes. Overall, these preliminary results demonstrate a significant impact of a supernumerary Y-chromosome on brain development, provide a neural basis for the motor, speech, and behavior regulation difficulties associated with 47,XYY, and may relate to sexual dimorphism in these areas.