The list of genetic mutations that can cause autism spectrum disorders (ASD) has expanded. A new study reveals that autism can be caused by more diverse genetic mutations that previously thought.
According to Psych Central, researchers from the University of California, San Diego School of Medicine performed a study on hundreds of volunteers from families with one child affected by ASD. The research team sequenced the complete genomes of every family member, including the normally developing siblings and the parents.
In this new study, the researchers looked for de novo mutations. These are defined as gene alterations appearing spontaneously in one's offspring. De novo mutations are due to a mutation in a mother's egg or a father's sperm.
Prior research has shown that de novo mutations contribute to increased risk of developing autism spectrum disorders, particularly in cases with no family history of autism.
A common type of the novo mutations is a "spelling mistake." In case of a spelling mistake, a single letter of the DNA code is changed. However, this latest research has found many other mutations introducing more complex changes.
These complex changes, rather than altering a single letter of the DNA code, involve the insertion or deletion of entire words or sentences of the DNA code. These alterations are called structural variants. The latest study found a large variety of such spontaneous mutations.
The researchers also found that structural mutations could sometimes occur in tight clusters. In these cases, a combination of different genetic mutations occurs all at once. The research team considers that their findings represent a significant advance in efforts to explain the autism spectrum disorder's genetic basis.
Senior author Jonathan Sebat, Ph.D., associate professor of psychiatry and cellular and molecular medicine at University of California, San Diego School of Medicine, explained that "these mutations can insert, delete, or in some cases scramble the DNA sequence."
The findings of the new research are published online in The American Journal of Human Genetics. In the future, additional research could lead to more effective and more personalized treatments for autism.
