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.