Association of polygenic scores for autism with volumetric MRI phenotypes in cerebellum and brainstem in adults.
Salahuddin Mohammad, Mélissa Gentreau, Manon Dubol and 3 others
PMID 39113134WHAT IT FOUND
Higher autism-related genetic predisposition was linked to slightly smaller total brain, white-matter, brainstem, and some cerebellum volumes, and more cerebrospinal fluid in ~31,000 adults.
The links were very small and not a diagnosis.
Key findings
01In the primary total-volume analyses, a higher autism-related genetic score was associated with smaller brain, white matter, brainstem, and cerebellar lobule I-IV, IX, and X volumes, and larger cerebrospinal fluid volume.
02In the secondary cerebellar sub-region analyses, a higher autism-related genetic score was associated with smaller left lobule I-IV, vermis VIIIb, and vermis X volumes.
03The genetic score accounted for only a tiny part of the primary volume differences, with reported values between 0.018% and 0.034%.
STILL TO COME
How it was doneWhat they found
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What it does not show
The findings are based on an autism-related genetic score, not on an ASD diagnosis, so they do not directly describe diagnosed adults or children. The UK Biobank sample was adults of European ancestry, aged 40-70 years, and the paper notes the cohort has higher average socioeconomic status and better health than the broader population. The study excluded people with dementia, Parkinson's disease, multiple sclerosis, epilepsy, stroke, head or neurological injury, trauma, or other chronic neurological problems, so it does not speak to patients with those conditions. The genetic score explained only a small share of brain-volume variation; the paper reports 2.5% compared with SNP-based heritability of 11%. The authors did not account for IQ, behavioural phenotypes, or life insults and socio-emotional behavioural damage that could influence brain volumes. The analysis reports associations between genetic scores and brain volumes; it does not test treatment or patient-level outcomes.
Declared interests
The supplied text does not include an author conflicts-of-interest declaration. The publication types list research support from non-U.S. government sources.
The easy way to misread this
Do not read these brain-volume differences as a diagnostic test for autism or a reason to change therapy. The study linked an autism-related genetic score to very small volume differences in adults whose outcomes were brain volumes, not ASD diagnoses, so it does not test whether brain volumes cause autism or whether any treatment works.