Loss of one copy of TBR1, an autism-linked gene involved in fetal brain development, leads to brain malformations, according to a study published in the September issue of Molecular Syndromology.

We are on the verge of a seismic shift in the definition of autism spectrum disorders, says David Skuse. Under proposed guidelines for autism diagnosis, the canard that most people with the disorder cannot speak, or have such disordered language that they cannot sustain a conversation, has been abandoned.

Geographical differences in autism prevalence can largely be accounted for by socioeconomic factors, according to research published 31 October in Environmental Health. The study confirms the importance of controlling for variables such as parents’ educational status when searching for environmental links to autism.

The loss of a 600-kilobase region on chromosome 16 leads to intellectual disability, obesity, a large head and, sometimes, autism, according to a study published in the October issue of the Journal of Medical Genetics.

Two new case studies highlight how complex rearrangements of chromosome 15 can lead to different disorders, including autism and the related Prader-Willi syndrome.

Mice missing the autism-linked gene CNTNAP2 have broad defects in their oxytocin system, according to research presented Tuesday at the Society for Neuroscience annual meeting in New Orleans. Treatment with oxytocin alleviates social deficits in these mice.

Traditional prenatal testing cannot distinguish between large disruptive chromosomal duplications and multiple harmless repeats, according to a study published 25 July in the European Journal of Human Genetics.

Characteristic symptoms of Phelan-McDermid syndrome — a disorder caused by the loss of the 22q13.3 chromosomal region — may include bipolar disorder and a sudden loss of skills during adulthood, according a study published in June in Molecular Syndromology.

Symptoms associated with a deletion of the 15q13.3 chromosomal region could result from the loss of a single gene, CHRNA7, according to a study published 9 July in Clinical Genetics.

Girls are less likely to be diagnosed with autism than boys are, unless they also have intellectual or behavioral problems, according to a study published 26 June in the Journal of the American Academy of Child and Adolescent Psychiatry.