Pinpointing the cause of autism has proven difficult, in part because it’s a complex group of developmental disorders and not a single condition.
Now, an international team of researchers says it has uncovered a “direct link” between autism and a gene known to play a role in brain development.
A small study of 10 kids — mostly boys — with autism showed that they had variants in the DDX53 gene, which is primarily expressed in the testis and brain. The researchers suggest that the gene may explain why boys are more likely to be diagnosed with autism than girls.
“By pinpointing DDX53 as a key player, particularly in males, we can better understand the biological mechanisms at play and improve diagnostic accuracy for individuals and their families,” said senior study author Stephen Scherer, chief of research at The Hospital for Sick Children in Canada.
Searches of autism research databases identified 26 more people who had rare DDX53 variants similar to the study participants.
An estimated 5.4 million American adults have autism, which affects learning, behavior, communication and interaction with others.
Diagnoses have skyrocketed in recent years due to changes in screening practices and diagnostic criteria, increased awareness and environmental factors.
Scherer said that identifying DDX53 as a “confirmed contributor to [autism] underscores the complexity of autism and the need for comprehensive genetic analysis.”
DDX53 is located on the X chromosome. At the same location, the researchers found evidence that another gene, PTCHD1-AS, might be involved in autism.
They highlighted the case of a mother and boy, both with autism, who had a gene deletion involving DDX53 and parts of PTCHD1-AS.
Their findings were published Thursday in the American Journal of Human Genetics.
Also Thursday in the same journal, researchers from the same team revealed 59 genetic variants on the X chromosome significantly associated with autism, including PTCHD1-AS (when it’s near DDX53).
Scherer said that “both studies provide even more evidence that complex neurobehavioral conditions like autism can sometimes have simple biologic (genetic) underpinnings.”
The researchers are calling for further investigation into DDX53 and other genes. One problem is that commonly used mouse models don’t have a gene like DDX53, which may make it difficult to develop therapeutics.
There is no cure for autism, but symptoms may improve with speech, occupational or physical therapy, behavioral interventions or medications.
