A new wave of genetic tests for fragile X syndrome, the leading cause of inherited mental retardation and the most common genetic cause of autism, may make it possible to routinely screen pregnant women and newborns for the syndrome.

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.

A point mutation in the autism-linked protein neuroligin-3 (NLGN3), seen in individuals with autism, causes the protein to misfold and localize to the wrong site in the cell, according to a study published in September in the Journal of Biological Chemistry.

Two new studies provide clues that may explain sex differences in autism prevalence. Italian researchers have found that injecting estrogen into the brains of young male mice reverses some of the structural and behavioral changes associated with low levels of reelin — a brain protein that has been previously implicated in autism — and the effects endure into adulthood.

Spontaneous harmful mutations are more frequent in individuals with autism and schizophrenia, according to two studies published in September.

A common variation within a region on chromosome 16 puts a large proportion of the general population at risk for intellectual disability, according to a study published in August in Nature Genetics.

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.

A study of postmortem tissue shows that microglia, cells that provide immune protection to the brain, are altered in the brains of individuals with autism.

Genes responsible for Alzheimer’s disease and fragile X syndrome — a form of mental retardation linked to autism — may operate through the same pathway, according to a study published in The Journal of Neuroscience.

A drug that interferes with a biochemical pathway important in cancer can reverse some brain defects in mouse models of fragile X syndrome, according to a study published 11 August in the Journal of Neuroscience.