Some forms of autism are caused by too many proteins at the synapse, the junction between neurons, whereas other forms result from too few, according to a study published 23 November in Nature.
Spectrum: Autism Research News
Rare or common, inherited or spontaneous, mutations form the core of autism risk.
Three mutations in SHANK2, an autism-associated gene, each lead to abnormal synapses, the junctions between neurons, according to a study in Human Molecular Genetics.
Regions of the genome that contain the same genetic variants on both copies of a chromosome are more likely to contain autism-associated genes than other parts of the genome, according to a study published 14 October in Human Genetics.
The brain abnormalities characteristic of tuberous sclerosis may begin early in development and involve malfunctioning of neuronal precursors, according to studies of two different mouse models of the disorder published in October.
More than 70 percent of individuals lacking the autism-associated 16p11.2 chromosomal region are overweight or obese, according to a study published 20 September in the Journal of Genetics and Genomics.
Researchers have derived neurons from stem cells to investigate mutations that lead to Rett and fragile X syndromes.
The etiology of autism may be best understood as an impairment of neuronal circuits, specifically interneurons that dampen signals in the brain, says neuroscientist Gordon Fishell.
Neurons from mice that model fragile X syndrome may fire signals more readily than neurons from controls, according to a study published 5 October in The Journal of Neuroscience. The results suggest a cause for the high incidence of seizures in individuals with the syndrome.