Autism is not caused by one or two gene defects but probably by hundreds of different mutations, finds a study.
The interactome or protein interaction network for autism spectrum disorders developed by researchers at Baylor College of Medicine and the Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital in collaboration with scientists at the Center for Cancer Systems Biology (CCSB) at Dana-Farber Cancer Institute demonstrates how protein pathways converge, diverge and interact to arrive at the same devastating condition.
Dr. Huda Zoghbi, director of the Neurological Research Institute and professor of neurology, neuroscience, molecular and human genetics and paediatrics at BCM, and her colleagues, described the findings.
The network also relays new information about idiopathic autism, which has no known cause.
It does this by building on what is known about syndromic autism that often occurs as a symptom of a broader genetic disorder such as fragile X, tuberous sclerosis and Phelan-McDermid syndrome.
The three core features of autism present in both idiopathic and syndromic cases include impaired social skills, delayed language and repetitive behaviours.
"The interactome is a more functional approach. It can help us understand how mutations in different genes can cause similar clinical symptoms," Zoghbi said.
"We had these 26 genes that seemed to have little to do with each other but still resulted in autism-like symptoms.
"We thought that perhaps they cause autism by interacting with some shared partners that function in pathways that lead to similar phenotypes (similar characteristics)," Zoghbi stated.
Compiling the interactome was a massive undertaking, said Dr. Chad A. Shaw, assistant professor of molecular and human genetics at BCM and a computational scientist who was a co-corresponding author of the study.
"One of the most important contributions of this interactome is that it provides a deep, experimentally driven foundation that can be used to understand complicated genetic variation," he said.
The findings have been published in the current issue of the journal Science Translational Medicine.