Women who have diabetes when pregnant are at an increased risk of having a child with autism, reports a study published 22 September in the Journal of Autism and Developmental Disorders.

Children who have older siblings with autism are seven times more likely than those in the general population to receive autism diagnoses themselves, according to a large Danish study published 19 August in JAMA Pediatrics.

Methylation — modifications to DNA that regulate gene expression — may explain why identical twins with the same Rett syndrome mutation have different symptoms, according to a study published 21 June in PLoS One.

Emerging evidence indicates that microglia, the brain’s immune cells, are altered in some individuals with autism, raising questions about their role in brain development, says Beth Stevens.

A new database pools health registry data from seven countries, dramatically boosting sample sizes for epidemiological studies of autism.

Watch the complete replay of Sarkis Mazmanian discussing new findings that support a connection between the gut microbiome and the autism brain. Submit your own follow-up questions.

Epigenetics, or the chemical markings on DNA that affect gene expression, plays a role in some cases of autism, according to a study of 50 identical twins published 23 April in Molecular Psychiatry.

A century-old drug created to treat African sleeping sickness reverses several autism-like features in a mouse model of the disorder, according to a study published 13 March in PLoS ONE.

Prenatal exposure of rats to the epilepsy drug valproic acid leads to behavioral and brain features that resemble autism, in males more than in females, according to a study published in the March issue of the Journal of Neurochemistry.

Folic acid supplements taken early in pregnancy reduce the risk of autism, according to a large Norwegian study published 13 February in the Journal of the American Medical Association.