New study shows link between gene mutations and autism symptoms

A new study has shed light on the link between abnormal brain development and key symptoms of autism spectrum disorder.

Scientists from the Florida campus of The Scripps Research Institute have studied the gene phosphatase and tensin homolog, which is disrupted in some individuals with autism, leading to mutations that cause excess growth within the brain.

Tests using animal models found that mutations in this gene cause increased brain size and social deficits, with males being more likely to show abnormalities related to repetitive behavior and mood/anxiety, while females exhibited more circadian activity and emotional learning problems.

It is surmised that these genetic abnormalities may desynchronise the normal pattern of growth in key cell types – possibly dopamine neurons – that are relevant for social behavior.

Study leader Damon Page, a Scripps Research Institute biologist, said: "Connections have to form in the right place at the right time for circuits to develop normally. Circuitry involved in social behavior may turn out to be particularly vulnerable to the effects of poorly coordinated growth."

It is estimated that around one in every 100 people has autism spectrum disorder, which manifests in problems with social interaction and communication, as well as a tendency towards repetitive patterns of thought and behaviours.