Sex chromosome trisomies are not associated with atypical lateralization for language.
Alexander C Wilson, Dorothy V M Bishop
PMID 29888392WHAT IT FOUND
Children with sex chromosome trisomies showed typical left-sided language brain activity, just like peers.
The condition did not cause atypical brain lateralization or handedness differences. Language difficulties in these children are not explained by reversed or bilateral brain organization.
Key findings
01There was no significant difference in language laterality indices between children with sex chromosome trisomies and the comparison group.
02The proportion of children classified as left-lateralized, bilateral, or right-lateralized for language did not differ between the groups.
03Handedness measures showed no significant differences between children with sex chromosome trisomies and the comparison group.
STILL TO COME
How it was doneWhat they foundWhat it means for SLPs
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What it does not show
fTCD measures blood flow in the middle cerebral artery, which covers a wide brain area, so it may miss fine-grained regional differences in lateralization. The study relied on a cross-sectional design, so it cannot determine how lateralization develops over time in these children. Children with SCT produced fewer valid trials and words during the language task, which could affect the robustness of the measurement, though reliability was high.
Declared interests
The authors declared no conflicts of interest. The study was supported by non-US government sources.
The easy way to misread this
Do not conclude that brain lateralization is irrelevant to language disorders in general. This study specifically addresses sex chromosome trisomies. It shows that typical left-sided organization persists in this genetic condition, but it does not rule out atypical lateralization in other developmental language disorders.