A teenager with fragile X syndrome carries a rare mutation that changes a single amino acid in the FMRP protein, researchers reported 22 January in the European Journal of Human Genetics.

It takes more mutations to trigger autism in women than in men, which may explain why men are four times more likely to have the disorder, according to a study published 26 February in the American Journal of Human Genetics.

The risk of certain autism spectrum disorders is highest in firstborn children and declines in each additional sibling born to the same mother, reports a large Finnish study published 28 January in Paediatric and Perinatal Epidemiology.

Adding to the complications of autism, overweight and obese children with the disorder are prone to a host of other troubles, including depression, anxiety and sleep problems, reports a study published 2 February in the Journal of Autism and Developmental Disorders.

In families with a history of autism, the affected children are seven times more likely to also have epilepsy than their unaffected siblings, according to a study published 1 December in Molecular Autism. The results suggest that epilepsy and autism share some risk factors.

Two large Scandinavian studies confirm the long-standing theory that older men have a higher risk of fathering children with autism, but they disagree on how a mother’s age drives risk of the disorder.

A shortage of trained doctors, lack of awareness and long waiting lists for specialized care delay diagnosis and treatment of autism in many low- and middle-income countries, report two new studies.

An updated version of a test that detects autism symptoms in toddlers is shorter, simpler and more accurate than its predecessor, making it easier for pediatricians to identify children in need of further testing, reports a study published in the January issue of Pediatrics.

A new research network aims to study autism’s least-understood population: those with the most severe forms of the disorder. Three experts weigh in on the project’s potential impact.

Some children diagnosed with autism may fall into distinct subgroups based on their symptoms and other diagnoses, researchers report in the January issue of Pediatrics.