PARIS, August 29 (Benin News) –
Researchers have identified a new group of moderately effective inherited genes linked to autism spectrum disorders and showing links to other behavioral disorders. They believe that these results demonstrate the need to involve a wide range of research participants across the spectrum to identify the full spectrum of autism genes.
In a series of papers published in the journal ‘Nature Genetics’, researchers used data from the Simons Powering Autism Research (SPARK) research cohort, which was created to advance our understanding of the complex genetics of autism and includes genetic data from nearly 43,000 people with autism. The results show differences in genetic influences between people on the autism spectrum.
“Autism is a spectrum, and includes people with profound autism who often have cognitive differences and/or epilepsy, as well as talented and exceptional people, often in specific areas. We now understand that genetic contributions to different phenotypes vary depending on the genes involved, when these genes are activated during brain development, and the frequency of certain genetic variants in the population,” explains SPARK’s principal investigator, Wendy Chung, PhD.
In one study, researchers analyzed the DNA of nearly 43,000 people with autism, including 35,000 participants in the SPARK Autism Study, as part of SPARK’s ongoing effort to understand the spectrum comprehensive review of autism genetics. This autism cohort, the largest ever, has allowed researchers to identify a group of new “moderate effect” genes that tend to contribute to autism through inherited variants.
It is widely known that autism is inherited, but previous studies have primarily identified autism genes with de novo variants (DNV) – variants that occur spontaneously in germ cells before conception – that are not not inherited. Most of these variants are also implicated in other neurodevelopmental disorders (NDDs).
Most of these genetic variants associated with autism have profound effects on the brains of those affected when they appear. However, only 20% of people with autism have this type of genetic variant.
“For many years we have known from twin studies that there must be inherited genetic variants that lead to autism, but we have not been able to systematically identify individual genes until now. now,” says lead author Pamela Feliciano, SPARK’s chief scientific officer. We have now identified a group of genes associated with autism, which may include inherited variants, and which begin to explain a different part of the autism spectrum.
To better understand the full spectrum of autism genes, the researchers analyzed 19,843 participants with autism, as well as one or both of their biological parents. They found that regarding 20% of people with autism have de novo genetic variants that affect the function of the associated gene.
Nearly 70% of this genetic contribution can be attributed to genes known for autism or neurodevelopmental disorders. However, this means that although known genes associated with autism are responsible for most de novo variants, there are others that have not yet been identified.
The researchers then added another 22,764 autistic people and 236,000 non-autistic people from the general population. In this meta-analysis, they identified 60 autism genes whose contribution to autism is largely due to rare inherited loss-of-function (LOF) variants inherited from parents who do not show cognitive differences. or autism. Among these genes, five had not yet been implicated in neurodevelopmental disorders.
Autistic people who carry inherited variants in these “moderate effect” genes are less likely to show cognitive differences than autistic people who carry LOF variants in well-established autism genes, such as CHD8 and SCN2A.
“Most of the parents who passed on these genetic variants in our study do not have cognitive differences or autism, but we do know that these genes are associated with autism because we found that these variants are more frequently inherited by autistic children,” he explains.
“Our hypothesis is that people with autism who have these inherited genetic variants are not as likely to experience seizures and cognitive differences as people with de novo genetic variants. So far, our data strongly supports this hypothesis,” concludes Dr. Feliciano.
