At birth, children with autism have lower blood levels of a class of antibody produced in response to infection compared with healthy controls, according to a report published in December in Autism Research.

Doctors are more likely to miss autism in girls, even when their symptoms are as severe as those of boys, adding to the gender bias that exists in autism.

Individuals with a deletion in the 16p11.2 chromosomal region — which has been linked to autism in several studies — show features of autism spectrum disorders including language delay, according to a study published in October.

A new Swedish study finds that the number of children with autism in Somali communities is on the rise, but it’s not clear whether the cause is biological or social.

Cases of autism in some high-risk areas are leveling off, argues a new study published in November in Pediatrics.

Infection early in pregnancy is more harmful to the fetus than at later stages, triggering brain and behavioral changes in the offspring similar to those seen in people with schizophrenia, according to two mouse studies published in October. A third study suggests that exercise can mitigate some of these effects.

People with autism may belong to one of four distinct categories based on their medical history, according to a study published in the October Autism Research.

Two new studies use medical records from countries with nationalized health care to link autoimmune disease and obesity in parents to the likelihood of having a child with autism.

Chemicals produced by their mother’s immune system in utero alter the size of several key brain regions in people with schizophrenia, enlarging chambers that store cerebrospinal fluids, and shrinking parts of the cortex involved in processing emotion and memory.

The first study of autism in Oman reveals that only 114 children have been diagnosed with the disorder.