A man’s risk of fathering a child with autism begins to rise at age 30 and significantly increases after age 50, according to a report published online 30 November in Molecular Psychiatry.

The pattern of interactions among different genes in yeast cells changes in response to disease-like conditions, in this case a DNA-damaging agent, according to a study published 3 December in Science. Mapping epistasis — how various cellular factors work together — is key to understanding complex disorders, such as autism.

Two independent groups have created mice that have deletions or duplications in a large section of chromosome 16. Each team has produced an animal with a different set of features, some of which — such as large head size and repetitive behaviors — are reminiscent of people with autism.

Chromosome 15 may harbor one or more risk genes for autism, according to a new study of multigenerational inheritance in Utah. Researchers have gathered data on family pedigrees stretching back as far as nine generations, with up to five family members affected by the disorder.

A new mouse model of Angelman syndrome that knocks out a large stretch of a key chromosome is clarifying some of the molecular mechanisms underlying the more severe forms of the disorder.

Two independent teams have identified the genetic culprits of three rare, inherited diseases by sequencing the genomes of several members of the same family. As the cost of whole-genome sequencing plummets, this family-based approach will reveal candidate genes not just for rare diseases but for common, complex disorders such as autism, experts say.

How many people with autism are also obese?

Several genetic and animal studies in the past year have found intriguing ties between autism and DISC1, one of the oldest candidate genes for psychiatric disorders.

Individuals who carry a large and rare deletion on chromosome 16 that is associated with autism are likely to have developmental delays, be obese or both, according to two studies published last week in Nature.

Genetic variations that tweak the brain’s release of oxytocin — a hormone involved in social bonding and establishing trust — may increase the risk of developing autism or traits of the disorder, according to three new studies published in the past few months.