Some types of restricted and repetitive behaviors become more prevalent among autistic children and teenagers over time, depending on their age and intellectual ability, whereas others decrease.

For 40 years, the preponderance of autism research has focused on understanding the causes and characteristics of the condition rather than testing assessments or interventions in community settings.

Researchers can roughly project what autistic children’s lives will look like years down the road. But how good is their crystal ball — and what are its benefits?

Elizabeth Berry-Kravis has spent decades uncovering molecular clues to fragile X syndrome and crafting trials of treatments. Her efforts are paying off.

Girls and women with mutations in the autism-linked gene DDX3X may be particularly vulnerable to anxiety and self-harm.

A drug that prevents an enzyme from breaking down a key molecule involved in learning and memory improved cognition and behavior in a small study of men with fragile X syndrome.

A new protocol aims to help researchers include more autistic people — especially those who are minimally verbal or have intellectual disability — in imaging studies.

Motor and memory training early in life postpones the onset of difficulties in those areas in a mouse model of Rett syndrome, and stimulating neurons involved in those skills appears to mimic the effects of training.

There is not yet a single example of a gene that, when mutated, increases the likelihood of autism but not of other neurodevelopmental conditions, including intellectual disability.

Autism and other neurodevelopmental conditions are more common among children born by C-section than those delivered vaginally, but the procedure itself does not underlie the association, according to a new study.