Authors: Jean-Francois Lepage, David S. Hong, Mira Raman, Matthew Marzelli, David P.
Roeltgen, Song Lai, Judith Ross, and Allan L. Reiss.

Date of Publication: February 2014

From the abstract:

“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 agematched
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.”

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