Electrical signals in neurons rely on the proper function of voltage‐gated sodium channels. Mutations in the gene SCN1A, which encodes voltage‐gated sodium channel type 1 (Nav1.1 channels), cause Dravet syndrome — a severe childhood neuropsychiatric disorder characterized by epilepsy, cognitive deficits and autism‐like behaviors.

Autism can be caused by a number of different genetic alterations, some of which result in known syndromes. In 2011, a genetic study of a large sample of children in the Simons Simplex Collection, a database of genetic and clinical information from families that include one child with autism, showed a strong association between duplication of the Williams syndrome chromosomal region (7q11.23) and autism.

Neurons are resident cells of our nervous system that are connected to one another through a structure called the synapse. These synaptic connections form the basis of nervous system function. Early in development, synapses form in excess and a subset must be eliminated during a process of synaptic remodeling to achieve the precise wiring diagram characteristic of the mature nervous system. If this process is disrupted, aberrant synaptic connections may lead to severe disruptions in behavior and overall function of the organism.

Angelman syndrome is a severe neurodevelopmental disorder characterized by intellectual disability, motor dysfunction, seizures and the absence of speech, and it shows a high comorbidity with autism. The syndrome is caused by maternal deletion or mutation of a single gene that encodes ubiquitin protein ligase E3A (UBE3A). The paternal copy of UBE3A typically is silenced in neurons, and therefore the loss of maternal UBE3A results in a complete absence of the protein in most areas of the brain. UBE3A is an enzyme that targets proteins for degradation, a process that maintains normal functioning within cells.

Dennis Wall and his colleagues used machine learning to study gold-standard instruments used for assisting the diagnosis of autism. They learned that the number of behaviors that clinicians must assess to arrive at an accurate diagnosis may be far smaller than what is used today. Wall and his group hypothesized that this small number of behaviors, when run through a machine-learning classification tool, would provide a ‘digital phenotype’ that clinicians could use to better manage children on their waiting lists with risk for developmental delay including autism.

Certain gene mutations can compromise normal protein functioning, leading to heritable diseases. Although researchers have identified a few genes that are disrupted in some people with autism, for the most part, autism spectrum disorders remain genetically undefined. Mutations in the AUTS2 gene, which most likely result in truncated versions of the AUTS2 protein, have been found in several people who exhibit autism symptoms.

A major obstacle impeding the development of effective treatments for autism is the complexity of factors, such as genetic mutations, epigenetics and environmental influences that contribute to the disorder. However, research over the past few years suggests that ‘hot spots’ of cellular dysfunction are shared across autism spectrum disorders of different etiologies.

Despite tremendous efforts to genetically and phenotypically characterize individuals with autism, we are still at the earliest stages of understanding how autism occurs. The vast majority of individuals with autism have mutations in one copy of each of multiple genes (heterozygous mutations), and these mutations interact with each other in ways that we do not yet understand.

Motor stereotypies, a core feature of autism, are involuntary, repetitive movements that are often associated with self-injury. Treatments for these behaviors are limited and often inadequate, owing to a poor understanding of the underlying biological mechanisms.