The signal, called CD47, is disrupted in autistic people who have a larger-than-average head.

The gene, YTHDF2, has not previously been linked to autism.

The code may help scientists identify people with the autism-linked condition and recruit them into clinical trials.

The cells’ altered proliferation rates hint at ways to diagnose and potentially treat autism earlier.

The gene, YTHDF2, may be one of several that contribute to an autism subtype marked by an unusually big brain.

The loss of CHD8, a top autism gene, speeds up the production of certain neurons and leads to overgrowth in spheres of cultured brain cells.

Mutations in all three accelerate the maturation of inhibitory neurons, which could upset the brain’s balance of excitation and inhibition early in development.

In this edition of Null and Noteworthy, tests of intranasal oxytocin and an Angelman syndrome treatment fail to see results.

An autism-linked mutation could make the brain grow unusually large by prompting cells to express a chemical signal better known for its connection to cancer.

Mutations in CHD8 lead to brain overgrowth or undergrowth in mice, depending on how they affect the gene’s expression.