Deletions or duplications of chromosomal segment 16p11.2 — previously reported as a key autism region — are seen in people with developmental delays and speech and behavioral problems, but not necessarily autism. That’s the finding from two large studies published last week of people carrying these rare genetic variations.

Genetic analysis of one Belgian family with a history of autism has pinpointed a piece of DNA on chromosome 16, within a segment thought to be missing in about one percent of all cases of autism. The unpublished data was presented on Saturday at the World Congress of Psychiatric Genetics in San Diego.

Antibodies directed against the fetal brain are present in some mothers of children with autism, confirming previous findings and suggesting that the antibodies could be used as a marker for the disorder, according to unpublished research presented yesterday at the Society for Neuroscience meeting in Chicago.

Children with autism rely on conscious planning, rather than habit, to control their movements, according to the first brain imaging study to examine motor performance in the disorder.

In 1985, Simon Baron-Cohen, Alan Leslie and Uta Frith reported for the first time that children with autism systematically fail the false belief task.