Brain structure in triple X syndrome: regional gray matter volume and cortical thickness in adult women with 47,XXX karyotype

Abstract Background Changes in the brain structure of women with Triple X syndrome (karyotype 47,XXX) have been described in a few studies to date, including reduced total brain volume and regional reductions in gray substance in cortical and subcortical areas. However, the empirical evidence from adults is very limited and group comparison on a voxel-wise basis for gray matter volume and cortical thickness is still missing. Methods Using voxel-based morphometry (VBM) and surface-based morphometry (SBM), we investigated regional gray matter changes in a sample of n = 20 adult women (aged 18–49 years) with 47,XXX karyotype using T1-weighted 3T MRI scans. Results Compared to an age- and education-matched control group (and controlled for differences in total intracranial volume), the VBM revealed decreased regional gray matter volumes in the hippocampus, amygdala, parts of the basal ganglia, insula, prefrontal areas and cerebellum. To a lesser extent, we also noted specific reductions in cortical thickness in a smaller part of those regions. Conclusion The observed network is significantly involved in the processing of cognitive, affective, and social stimuli and might be a potential neuronal correlate of the autism-like social-cognitive problems described in 47,XXX in the literature.