A new study led by Columbia researchers has uncovered 60 genes linked to autism that may provide important clues to the causes of autism across the full spectrum of the disorder.

“Overall, the genes we found may represent a different class of genes that are more directly associated with the core symptoms of autism than previously discovered genes,” says Wendy Chung, MD, PhD, the Kennedy Family Professor of Pediatrics and chief of clinical genetics in the Department of Pediatrics at the Columbia University Vagelos College of Physicians and Surgeons.

The findings were published Aug. 18 in Nature Genetics.

Several genes have been previously linked to autism and are responsible for about 20% of all cases. Most individuals who carry these genes have profound forms of autism and additional neurological issues, such as epilepsy and intellectual disability.

To uncover hidden autism genes that can explain most cases, the researchers tapped into data from nearly 43,000 people with autism, including 35,000 individuals from the SPARK autism research study of the Simons Foundation.

Five genes identified by the new study have a more moderate impact on autism characteristics, including cognition, than previously discovered genes.

“We need to do more detailed studies including more individuals who carry these genes to understand how each gene contributes to the features of autism, but we think these genes will help us unravel the biological underpinnings that lead to most cases of autism,” Chung says.

The five newly identified genes also explain why autism often seems to run in families. Unlike previously known autism genes due to de novo or new mutations, genetic variants in the five new genes were often inherited from the participant’s parents.

Chung says that many more moderate-effect genes remain to be discovered and finding them should help researchers better understand the biology of the brain and behaviour across the full spectrum of autism.