Betty Diamond and her colleagues at The Feinstein Institute for Medical Research in Long Island, New York, demonstrated the presence of antibodies that bind to brain tissue in the blood serum of approximately 10 percent of mothers of a child with autism spectrum disorder. More than half of these women also have anti-nuclear antibodies. Autoimmune disease is also more prevalent in these women than in the general population.

Mutations in certain genes that encode proteins at the synapse, the junctions between neurons, are known to be associated with autism spectrum disorders. Two such families of proteins, neurexins and neuroligins, are thought to be important for assembling synapses. However, the role of these molecules in synapse formation and overall neuronal function is still poorly understood.

There is currently no cure for any autism spectrum disorder, and the current pharmacological treatments have had limited success. Finding treatments for autism has proven challenging for two major reasons. First, defects in multiple genes increase risk for autism, which makes it difficult to study and identify effective treatments. Second, drug screening in neurons, which are non-dividing cells, poses immense technical challenges. Benjamin Philpot and his colleagues at the University of North Carolina have sought to overcome these challenges by developing a novel neuronal drug screen to identify small-molecule compounds for treating autism caused by dysregulation of a single gene, UBE3A.

The most common inherited form of autism is fragile X syndrome, which is caused by genetic inactivation of the fragile X mental retardation protein (FMRP). In addition to intellectual disability, children with this disorder exhibit extreme social anxiety, poor eye contact, repetitive behaviors, hand flapping and tactile avoidance — hallmark characteristics of people with autism.

Autism impairs the development of social behavior, emotions and communication. The prefrontal cortex plays an important role in the early development of these skills and displays abnormal growth and function in children with autism. Few studies have looked for autism-associated neural defects in this region in young children.

Children with autism and related disorders often have problems with language acquisition. Simon Fisher of Oxford University and his colleagues are aiming to uncover the neural mechanisms of abnormal language development by studying the key genetic pathways that can go awry in these disorders.

Luis Parada and his colleagues at the University of Texas Southwestern Medical Center in Dallas have been studying the brain morphology and behavior of mice with mutations that are specific to certain brain regions. In previous work, they generated a mouse line in which PTEN was deleted in neurons of the cortex and hippocampus.

The underlying causes of autism spectrum disorders are poorly understood, but one appealing hypothesis is that an imbalance of excitation and inhibition in the brain’s cortex underlies a significant proportion of autism cases.

A number of the genes that have been implicated in autism have counterparts in model organisms, such as mice and fruit flies. This evolutionary conservation allows researchers to gain insights into the molecular pathways in which these autism-linked genes function. Lawrence Zipursky, of the University of California, Los Angeles, and his colleagues are studying one such conserved gene and its role in brain development.

Flora Vaccarino and her colleagues at Yale University have developed and characterized several lines of human induced pluripotent stem (iPS) cells from the skin cells of two individuals with autism and their family members, all from the Simons Simplex Collection. These two individuals show a larger-than-normal head circumference.