Researchers have said that autism has many different genetic forms that "autisms" is a more appropriate term to use than the singular term.
Study researcher Stephen Scherer, the director of the Center for Applied Genomics at the Hospital for Sick Children in Toronto, and colleagues have earlier identified over 100 genetic mutations that can make a person more susceptible to the disorder.
Findings of their new study published in the journal Nature Medicine on Jan. 26 has revealed that even brothers and sisters who are diagnosed of autism do not always have the same autism-linked genes.
The researchers in particular found that two-thirds of siblings with autism spectrum disorder, or ASD, have different genetic changes showing that genes associated with autism may vary among family members regardless that they are expected to be genetically similar.
Scherer said that when a family has a child diagnosed with autism, doctors traditionally focus only on the gene linked with the child's autism to predict if another child from the same family could also be at risk of the condition. He said that the study could lead to improve diagnosis and earlier treatment for children who are genetically predisposed towards the developmental disorder.
"We believe a better term to use is 'the autisms,' or 'the autism spectrum disorders' (that is, plural)," Dr. Scherer told Reuters. "There are many different forms of autism. In other words, autism is more of a collection of different disorders that have a common clinical manifestation."
Scherer and colleagues involved 85 pairs of siblings with ASD and their parents. They found that only 36 of the 85 families had mutations that can be associated with genes that are already linked to ASD. When they looked at these 36 families, the researchers found that only a third of the sibling have the same mutations showing that the kids have different forms of autism and require to be treated in their own special way.
"Our study emphasizes that substantial genetic heterogeneity exists in ASD, necessitating the use of whole-genome sequencing (WGS) to delineate all genic and non-genic susceptibility variants in research and in clinical diagnostics," the researchers wrote.
Figures from the U.S. Centers for Disease Control and Prevention (CDC) show that one in 68 children in the U.S. has ASD, a condition marked by difficulty in communicating with others and repetitive and obsessive behaviors.
