Quantitative analysis of gray and white matter in Williams syndrome.

Williams syndrome is a developmental disorder with a genetic basis, which results in an uneven cognitive profile with relatively strong language skills and severely impaired visuospatial abilities. To better understand the brain structure underlying this profile, we compared individuals with Williams syndrome with controls using multimodal neuroimaging data and new analytic methods (diffeomorphic mapping and atlas-based analysis). People with Williams syndrome had basal ganglia atrophy, while the fusiform, the medium temporal gyri, and the cerebellar cortex were relatively preserved. The right superior longitudinal fasciculus, the left frontooccipital fasciculus, the caudate, and the cingulum demonstrated increased fractional anisotropy, whereas the corticospinal tract revealed decreased values. These findings may be linked to the uneven cognitive profile evident in Williams syndrome.