The research on discovering the specific genes that can cause autism has long been hampered by the lack of proper technology and the unwillingness of families to have their members with autism tested.
Finally, progress on the project has been made, with researchers from over 50 laboratories saying that they have identified over 100 genes that show mutations in children suffering from autism, which is many more compared to how many genes were previously known.
The mutations that the scientists have identified are those that suddenly occur, and not those that the children's parents pass down to them. These spontaneous mutations have caused at least 30 percent of all cases of autism, according to scientists from the Cold Spring Harbor Laboratory.
One study discovered that a certain group of mutations leads to autism in high-functioning, high-IQ boys, while another group is able to influence the development of autism in both boys and girls bearing low IQ.
According to Cold Spring Harbor Laboratory researcher Michael Ronemus, there is a bit of a difference in the mechanism of which genes are affected, and how the functions of the affected genes are altered.
Ronemus is the lead author of The contribution of de novo coding mutations to autism spectrum disorder, one of the many studies on the topic that was published on the journal Nature.
Findings show that girls have a lower chance of acquiring autism compared to boys, with the study discovering that mutations that develop in girls affect the genes that have a significant part in the early days of the embryo within the womb.
Researchers believe that girls have an innate protection against autism, which means that such a drastic mutation is required to lead to the development of autism.
"What is the amazing thing about autism genetics is that in many cases you disrupt just one copy of the gene, you cause some sort of dysfunction," Ronemus explained. This is different compared to other genetic disorders, as others require mutations to occur on both copies of a certain gene to be able to develop into the disorder.
Ronemus and the other scientists that worked on the study tested genes obtained from over 3,000 subjects, which includes children diagnosed with autism, their parents, and a sibling with no autism.
The mutations were compared with the family members to discern which ones were passed down, and then compared between all subjects with autism to determine the shared mutations.
Scientists have started using faster but also cheaper technology to scan genes to look for the mutations, with Ronemus stating that the developments in the research have allowed scientists too know where to look.
"If we have better genetic screening when a child is diagnosed with autism we might be able to say, here is the behavioral intervention they need," said Ronemus.
"We already know that if you intervene early on you can produce a more optimal outcome."