title: Regionally specific increased volume of the amygdala in Williams syndrome: evidence from surface-based modeling.
abstract: Williams syndrome (WS) is a condition caused by a contiguous deletion of approximately 26-28 genes from chromosome 7, and is characterized by abnormal social and emotional processing and abnormal structure and function of the amygdala. Prior studies show that the amygdala is relatively enlarged in WS, but very little is known regarding the regional specificity of increased amygdalar volume in this condition. Here we investigated the regional specificity of structural alterations of the amygdala in WS, compared to a typically developing (TD) control group. We acquired high resolution brain MRI data from 79 participants (39 WS, 40 TD) and used a surface-based analytical modeling approach. The WS group exhibited several areas of increased radial expansion of the amygdalar surface and no areas of decreased radial expansion of the amygdalar surface compared to TD controls. The areas found to exhibit particularly increased radial expansion in WS included the bilateral posterior cortical nucleus, lateral nucleus, and the central nucleus. This greater regional and anatomical specificity of altered amygdala structure in WS contributes to a model relating genetic risk in WS to the development of key brain regions for social and emotional functioning.
authors.affiliation: Center for Interdisciplinary Brain Sciences Research (CIBSR), Stanford University School of Medicine, Palo Alto, California; Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, California; Department of Psychology, University of Georgia, Athens, Georgia.
authors.forename: Brian W
authors.initials: BW
authors.lastname: Haas
authors.forename: Kristen
authors.initials: K
authors.lastname: Sheau
authors.forename: Ryan G
authors.initials: RG
authors.lastname: Kelley
authors.forename: Paul M
authors.initials: PM
authors.lastname: Thompson
authors.forename: Allan L
authors.initials: AL
authors.lastname: Reiss
mesh_terms: D000293:Adolescent; D000328:Adult; D000679:Amygdala / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008297:Male; D018980:Williams Syndrome / Q000473:pathology* / Q000503:physiopathology; D055815:Young Adult