A mother’s exposure to infection can exacerbate the effects of a genetic mutation and contribute to autism or schizophrenia in her pups, suggests an unpublished mouse study presented Wednesday at the 2013 Society for Neuroscience annual meeting in San Diego.

Cells extracted from baby teeth, which fall out on their own, may be better suited than skin cells for making induced neurons to use in autism research, suggests a study published 3 October in PLoS One.

Deletion of a gene in 22q11.2, a chromosomal region linked to autism and schizophrenia, leads to small head size in mice, according to research presented Saturday at the 2013 Society for Neuroscience annual meeting in San Diego. Mice with a large deletion in this region show disrupted brain connections, and struggle with learning and memory.

Researchers have mined the medical records of more than 100 million people and found close to 3,000 associations between single-gene diseases, such as cystic fibrosis, and complex genetic disorders such as autism. The results were published 26 September in Cell.

Researchers weigh in on the mounting evidence for a paternal-age effect in autism and what it might reveal about evolutionary mechanisms underlying the disorder.

Triggering immune defenses in pregnant monkeys can lead to repetitive behaviors and social problems in their babies, according to a study published 4 September in Biological Psychiatry.

More of the common variants implicated in schizophrenia are also linked to bipolar disorder than to autism, according to a study published 28 August in Nature Genetics.

An enzyme that may keep RNA tangle-free as it’s translated into protein is missing in some people with schizophrenia and learning difficulties. The enzyme also cooperates with the protein missing in fragile X syndrome to bind RNA, suggesting a role in protein synthesis. That’s the upshot from two studies published in the September Nature Neuroscience.

Despite a sizable overlap in symptoms and medications, autism, bipolar disorder and schizophrenia each has a defining signature. The findings are based on an analysis of electronic medical records from California hospitals, published 16 August.

Certain mutations may hijack the normal mechanisms of sperm production, leading to an enrichment of mutant sperm in older fathers, and to the paternal-age effect in autism.