In a major study in genetic sequencing analysis, researchers from the Canadian Hospital for Sick Children- SickKids have revealed new genes and genetic changes associated with autism spectrum disorders, and this study provides a better understanding of the genetic structure behind these disorders.
The study was published in the "Cell" magazine on the tenth of November, and the "EurekAlert" website wrote about it.
concept of autism
According to the World Health Organization, “Autism spectrum disorders are neurodevelopmental disorders, meaning that they result from abnormalities in the way the brain develops and functions.”
People with autism spectrum disorders have problems with social behavior and communication with others and tend to get involved in individual interests and activities that they do over and over again.
According to the organization, one in every 160 children suffers from autism spectrum disorders.
The study examined the complete sequence of genes of more than 7,000 people with autism, in addition to studying the genetic sequence of more than 13,000 family members of affected children.
The team found 134 genes associated with autism spectrum disorders, and they also revealed a set of genetic changes that are likely to be associated with autism, the most common of which was gene copy number variations, and also included rare genetic changes associated with autism spectrum disorders found in 14% of the participants diagnosed with autism.
Most of the analyzed data was extracted from the MSSNG database provided by Autism Speaks, which is the largest database in the world that provides complete gene data for autism patients and gives researchers access to thousands Genetic sequences for free.
Unknown changes
Dr. Stefan Scherer, senior researcher in genetics and molecular biology, says, "By analyzing the complete sequence of the genes of all the participants and with the participation of the affected families in the databases, which constituted the researchers' priorities, we made the most of the capabilities to discover and analyze all kinds of genetic changes that we encountered, from change Little in the DNA and even changes that affected the entire genetic material.
Dr. Brett Troost, principal investigator of the study and co-investigator of the Genetics and Biological Genetics Program at the Hospital for Sick Children, noted that using whole-genome sequencing allowed the researchers to uncover unknown changes that would not otherwise be seen.
These changes include complex changes in the ordering of the DNA as well as extended, consecutive repeats, a finding that has been supported by the results of recent research linking autism to the repetition of certain segments of DNA multiple times.
A study of the role of mitochondrial DNA inherited from the mother showed that it has a contribution to autism estimated at 2%.
The research paper indicated important subtle differences in the inheritance of autism in families with one affected individual, compared to families with more than one autistic member.
The research team was surprised that when the "polygenic score" - which expresses the likelihood of a person being diagnosed with autism - was calculated by collecting the effects of thousands of genetic changes, these scores were not higher in families of more than one autistic individual.
Dr. Trost suggests that families with more than one affected individual may have autism associated with a significant inherited genetic change.
Because the genetics and clinical traits associated with autism are very complex and varied, the presence of large data such as those used in this research has an important role in providing a clearer understanding of the inheritance of autism.
In a related context, Dr. Scherer's research team found that a group of rarely and automatically inherited genes and a group of genetic factors at the same time may lead to different subtypes of autism.