Rare damaging genetic variants in genes linked to severe brain-development conditions are also tied to lower cognitive test scores across the general population, according to a study in Nature Genetics.

Researchers at the Wellcome Sanger Institute mapped genetic variants across nearly half a million people. They found that damaging DNA differences in the same genes that cause serious neurodevelopmental conditions can also affect cognitive traits more broadly.

"Learning more about these impacted genes could help us better understand how the brain develops," said co-senior author Dr Hilary Martin, "and why DNA changes in these genes lead to neurodevelopmental conditions in some people but not others."

The study used imputed fluid-intelligence scores to reduce bias and increase statistical power. It is one of the largest analyses of rare variants and cognition to date. The findings do not mean genes determine destiny; they point to biological pathways that shape how brains develop, which could one day guide earlier support for children who need it.

Sources: medicalxpress.com.