Children born to fathers older than 45 years have a heightened risk of developing a range of conditions, from autism to addiction, according to a large Swedish study published 1 April in JAMA Psychiatry.

Among the younger siblings of children with autism who do not have the disorder themselves, more than one-quarter show developmental delays at their first birthday, according to a study published in April.

An automated system developed for tracking the movements of lab animals can be used to accurately map the activity of children with autism, researchers reported in the February Molecular Autism. When given free rein, the system found, children with autism tend to explore a room’s edges, whereas those with other developmental disorders cling to their parents.

Young boys continue to have the highest rate of autism diagnoses, but Danish doctors are diagnosing more girls, teenagers and adults with the disorder than they did in the mid-1990s. That’s the finding from a 16-year study published 20 February in the Journal of Autism and Developmental Disorders.

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.

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.

Mutations in two proteins that help guide neurons as they grow in the developing brain may be risk factors for autism, according to a study published 14 January in Human Molecular Genetics.

Children of women who have attention deficit hyperactivity disorder are at increased risk for autism and attention deficit, according to a study published 21 January in the Journal of Child Psychology and Psychiatry. This suggests the two diseases have common risk factors.

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.

Carrying a duplication of the 22q11.2 chromosomal region may protect against schizophrenia, suggests a study published 12 November in Molecular Psychiatry. This is the first evidence of a genetic region that lowers the risk of a disorder rather than increases it.