CYTOARCHITECTONIC ANOMALIES IN A GENETICALLY BASED DISORDER - WILLIAMS-SYNDROME

WE report on cytoarchitectonic neocortical findings in a patient with Williams syndrome (WS), a rare genetic disorder resulting in character istic facies, heart defect, other connective tissue anomalies, and a u nique neurobehavioral profile. Cytoarchitectonic anomalies include exa ggerated horizontal organization of neurons within layers, most striki ng in area 17; increased cell packing density throughout brain regions ; abnormally clustered and oriented neurons. Overall, posterior forebr ain areas were markedly diminished in volume. The results suggest that brain anomalies may relate to the extreme visuospatial deficit in WS, the dysregulation of apoptotic cell death, and the genetic basis of W S, a hemizygous deletion including the elastin locus on chromosome 7. This case provides opportunities for linking brain findings to cogniti ve deficits and their genetic underpinnings.