A new model system allows scientists to watch human neurons develop outside of the brain, researchers reported Sunday at the Society for Neuroscience annual meeting in San Diego.

Scientists have pinpointed two major gene networks relevant to autism by analyzing gene expression in brain tissue from individuals with the disorder. Researchers presented the data Sunday at the Society for Neuroscience annual meeting in San Diego.

Loss of activity of FOXP1, a member of a family of genes that regulate gene expression, leads to general behavioral defects, including delays in language, according to a study published in November in The American Journal of Human Genetics.

Mice missing a large protein at the junction between neurons show motor impairments, anxiety and increased social behaviors, according to a study in the American Journal of Psychiatry. The protein, postsynaptic density-95 or PSD-95, is part of a key molecular bridge connecting other proteins linked to autism.

Early data suggest that it is possible to identify autism by looking at gene expression in the blood. But it’s going to take more work to prove it.

People with autism show differences in the levels of various gene products compared with their unaffected siblings, according to a study published online in September in Brain Research.

A study of postmortem brain tissue shows that RPP25, a gene on the autism-linked 15q22-26 chromosomal region, is expressed differently in the brains of people with the disorder. This is the first time this gene has been implicated in autism.

The protein missing in fragile X syndrome is necessary for the proper development of neural stem cells — self-renewing cells that can differentiate into more specialized types, including neurons — according to a paper published in the August issue of Human Molecular Genetics.

Mouse models of fragile X syndrome show defects in two kinds of potassium channels — ubiquitous pores that control the flow of electrical current across neurons — in a brain area that processes sound, according to two papers published this summer.

In the not-too-distant future, we may be able to diagnose toddlers with autism using a simple clinical test — based on voice patterns, blood or even urine.