Williams syndrome: a relationship between genetics, brain morphology and behaviour.
Williams syndrome brains show smaller, extra-folded parietal lobes, so plan for clear visual supports when you teach spatial tasks.
01Research in Context
What this study did
Early et al. (2012) scanned the brains of children with Williams syndrome. They compared each brain to a typically developing child of the same age.
The team measured cortical thickness, surface area, and how folded the parietal lobe was. They wanted to see which parts of the brain looked different.
What they found
Kids with Williams syndrome kept normal cortical thickness. Their brain wrinkles were not thinner, just shaped differently.
Surface area and volume were smaller. The parietal lobe was extra folded. The authors link this pattern to early cell-migration rules called the radial-unit theory.
How this fits with other research
Bleyenheuft et al. (2013) saw a similar story in Down syndrome. Those kids also struggle with flexible maps, but the problem shows up in virtual mazes instead of brain folds.
Bai et al. (2023) and Seng et al. (2022) found the opposite picture in autism: more gray matter or altered volume in social areas, yet both groups share visuospatial hiccups. The difference is location—autism changes frontal and social hubs, Williams syndrome changes parietal spatial hubs.
Baker et al. (2010) adds a twist in dyslexic adults: extra gyral depth, not extra folding. All three papers say the same thing in different words—when folding goes off-script, spatial or reading skills suffer.
Why it matters
If you work with a child who has Williams syndrome, expect puzzles, maps, and drawing tasks to be hard. The brain scan tells you the parietal hardware is smaller and overly folded, so give extra visual cues, break spatial tasks into tiny steps, and teach compensatory verbal strategies. Pair the child with a peer for spatial games and celebrate small wins to keep motivation high.
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02At a glance
03Original abstract
BACKGROUND: Genetically Williams syndrome (WS) promises to provide essential insight into the pathophysiology of cortical development because its ∼28 deleted genes are crucial for cortical neuronal migration and maturation. Phenotypically, WS is one of the most puzzling childhood neurodevelopmental disorders affecting most intellectual deficiencies (i.e. low-moderate intelligence quotient, visuospatial deficits) yet relatively preserving what is uniquely human (i.e. language and social-emotional cognition). Therefore, WS provides a privileged setting for investigating the relationship between genes, brain and the consequent complex human behaviour. METHODS: We used in vivo anatomical magnetic resonance imaging analysing cortical surface-based morphometry, (i.e. surface area, cortical volume, cortical thickness, gyrification index) and cortical complexity, which is of particular relevance to the WS genotype-phenotype relationship in 22 children (2.27-14.6 years) to compare whole hemisphere and lobar surface-based morphometry between WS (n = 10) and gender/age matched normal controls healthy controls (n = 12). RESULTS: Compared to healthy controls, WS children had a (1) relatively preserved Cth; (2) significantly reduced SA and CV; (3) significantly increased GI mostly in the parietal lobe; and (4) decreased CC specifically in the frontal and parietal lobes. CONCLUSION: Our findings are then discussed with reference to the Rakic radial-unit hypothesis of cortical development, arguing that WS gene deletions may spare Cth yet affecting the number of founder cells/columns/radial units, hence decreasing the SA and CV. In essence, cortical brain structure in WS may be shaped by gene-dosage abnormalities.
Journal of intellectual disability research : JIDR, 2012 · doi:10.1111/j.1365-2788.2011.01490.x