Including more females in autism research studies will aid the search for genetic and environmental susceptibility factors for the disorder, says genetic psychiatrist Lauren Weiss.

The study of any genetic disorder benefits from including the many diverse human populations in our world, and autism should be no different, says geneticist Christopher Walsh.

Deletions or duplications of the UBE3A gene lead to both Angelman syndrome and some cases of autism, respectively. Studying the effects of altered gene dosage in this region will provide insights into brain defects and suggest targets for therapies for both disorders, says expert Benjamin Philpot.

Studying the infant siblings of children who have autism to identify early signs of the disorder is expected to have enormous impact on the field from a clinical and a basic science standpoint, says psychologist Karen Dobkins.

Several targeted trials on drugs that treat fragile X syndrome are under way. But accurate endpoints to measure the drugs’ effectiveness are crucial, argues developmental and behavioral pediatrician Randi Hagerman.

What’s known about the genetics of autism supports the ‘snowflake’ hypothesis — that the molecular underpinnings of disease are essentially unique from individual to individual — says human geneticist Brett Abrahams.

Autism is diagnosed based on the severity and variety of its symptoms. This makes it very difficult to diagnose and easy to confuse with other disorders, such as language delay and intellectual disability, cautions Isabelle Rapin.

Good mouse models of autism, and accurate tests to assay their phenotypes, are key to both narrowing down a cause and developing effective treatments, argues expert Jacqueline Crawley.

No matter which of the numerous genetic and environmental risk factors has caused autism, the part of the system that is always affected is most likely to be found at the cognitive level, argues Uta Frith, a leader in the field of cognitive neuroscience.

There does not appear to be a single genetic or environmental cause of autism, and given the heterogeneity of symptoms, coming up with a clear yes or no test for autism is challenging. Timothy Roberts argues that imaging and electrophysiology are key in the search for autism biomarkers.