Autism: Beyond the Genes
As scientists look for genes that may be responsible for Autism Spectrum disorders or ASD, a new study points to regions of DNA outside of genes. That may be confusing because normally with genetic disorders, you think of single gene mutations that cause disease, for example, sickle cell disease. However, in ASD, the genes involved that we know about so far only account for a small fraction of new cases. So, the question is can mutations in other regions of the DNA contribute to ASD?
To answer that question, scientists analyzed the genomes of eighteen hundred families that have one child with ASD. They used an artificial intelligence approach called deep learning which applies an algorithm in successive analyses to find subtle patterns we'd miss.
The algorithm taught itself to identify regions of the DNA to which over two thousand proteins could bind. How they bind is key to how genes are used. The program also learned to predict which mutations would disrupt that binding process and gave a 'disease impact score.'
Then, they sorted over one hundred twenty thousand mutations that could affect gene are used in these families' DNA. They discovered significant numbers of mutations in areas of DNA that don't code for genes. For example, there's a significant connection between non-gene mutations and IQ. This supports the finding that forty to sixty percent of people with ASD have an intellectual disability.
It is likely ASD results from many combinations of mutations, gene and non-gene. The bad news is, this also means gene therapy won't likely cure Autism.
More Information
Artificial intelligence detects a new class of mutations behind autism
Many mutations in DNA that contribute to disease are not in actual genes but instead lie in the 99% of the genome once considered 'junk.' Even though scientists have recently come to understand that these vast stretches of DNA do in fact play critical roles, deciphering these effects on a wide scale has been impossible until now...
Whole-genome deep-learning analysis identifies contribution of noncoding mutations to autism risk
Great progress has been made in the past decade in understanding the genetics of ASD, establishing de novo mutations, including copy number variants (CNVs) and point mutations that likely disrupt protein-coding genes, as important causes of ASD1,2. However, when combined, all the known ASD-associated genes explain only a small fraction of new cases and it is estimated that, overall, de novo mutations in protein-coding genes (including CNVs) contribute to no more than 30% of simplex ASD cases2,3. The vast majority of identified de novo mutations are located within intronic and intergenic regions; however, little is known regarding their contribution to the genetic architecture of ASD or for any other complex disease...