Among its many unusual symptoms, the genetic disorder called Williams syndrome robs people of depth perception and the ability to visualize how different parts assemble into larger objects, as in a simple jigsaw puzzle.
An unusual scarcity of tissue in a small corner of the visual system underlies this particular problem in individuals with Williams syndrome, a new brain-imaging study finds. It appears that, at least with respect to vision, this genetic condition creates a slight defect in an otherwise typical brain.
In contrast, some researchers have proposed that a unique course of brain development occurs in Williams syndrome, which is linked to a missing, roughly 20-gene section of chromosome 7 (SN: 2/26/00, p. 142: Available to subscribers at Genes to Grow On).
"A very circumscribed abnormality of visual processing characterizes the brain in Williams syndrome," says neuroscientist and study director Andreas Meyer-Lindenberg of the Na