An international team of researchers shed new light on the genetic relationship between autism spectrum disorders (ASD) and related traits in the general population, revealing that autism genes are actually present in everyone.
In a study published in the journal Nature Genetics, the researchers explored the presence of a genetic link between ASD and how traits to the condition were expressed in groups of people not diagnosed with ASD. Their findings suggest that an underlying genetic risk in ASD affects a number of developmental and behavioral traits in the general population, and those with the condition account for the traits' severe representation.
ASD is a group of neurodevelopmental conditions that manifests in one out of every 100 children. Characterized by language and communication impairments, difficulty in social interaction and repetitive and stereotyped behavior, symptoms are at the center of defining ASD but they also occur in certain degrees in individuals not diagnosed with the condition.
Recent strides in analyzing genomes have shown that majority of ASD risk is polygenic or the result of the combined effects of smaller but thousands of differences in genetics. However, some cases are linked to rare genetic variants with significant effects as well.
Once measurable genetic signatures were acquired, the researchers were able to show that the genetic risk promoting autism is one that is present in everyone, said Mark Daly, the study's senior author.
Using cognitive and behavioral data from the general population, researchers can now untangle mechanisms responsible for the operation of genetic risk. According to Elise Robinson, the study's co-first author, they now have a better guide to follow when it comes to expecting what trait and disorder types will have associations with different genetic risk types.
For the study, the researchers used data from the Avon Longitudinal Study of Parents and Children, a Bristol-based general population cohort, and the Simons Simplex Collection of ASD cases and unaffected siblings, a nuclear family cohort, as well as international studies on the genetics of autism, Denmark's iPSYCH autism project, the Psychiatric Genomics Consortium Autism group and the Autism Sequencing Consortium.
The researchers expect that the approach they used for their work can be used in exploring the same associations in other disorders like schizophrenia.
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