Study Finds Common Gene Variants In Autistic Children

Scientists have long known that people with autism have brains that work differently – their brain activity doesn’t follow usual pathways for thought, speech or social interaction – but they haven’t known why.

While there is currently no way to predict the disabling disease, scientists have found promising genetic clues that may improve diagnosis and offer the promise of developing treatments for the frustratingly mysterious disorder.

Research published in the online medical journal Nature, compared the genomes of thousands of children with autism to those without the disorder – a massive task that has only recently been possible. The genome is the genetic material contained in an organism, including its chromosomes, genes and DNA.

By comparing the DNA of children with and without autism, researchers identified several genes related to autism. Scientists say that autism, a complex disorder, could be caused by as many as 50 genes.

The findings point researchers in the right direction toward developing drugs to treat the disorder in the future.

The first of two Nature studies found that 65 percent of autistic participants shared a variation between the region of chromosome 5 involving the genes that facilitate cell-to-cell communication -- CDH9 and CDH10. Those molecules help brain cells to connect and autism researchers have long suspected that trouble there may be linked to the disorder.

The second study suggests a link between autism and an excess in genetic material associated with the ubiquitin, a protein involved with cell – adhesion molecules and connections between brain cells.

The studies do not explain the rising number of diagnosed autism cases. It may be the result of heightened awareness of the disorder, because the definition of autism has expanded or due to an environmental factor. Or it may very well be some combination of these factors or something else entirely.

Autism a brain disorder that affects a person's ability to communicate, form relationships, and respond to the environment. Individuals can have mild, moderate or severe autism. It is four times more prevalent in boys than girls.

Some people with autism are highly functional while others are mentally retarded, mute, or have severe problems with language.

An estimated one out of every 150 U.S. children has autism, according to the U.S. Centers for Disease Control and Prevention (CDC).

A study last year suggested that for some autistic children, the disorder originates from gene defects that can be switched on and off by mental activity. The findings support previous research that autism may result from problems in the complex process by which some networks of brain cells grow and others die during the first few years of a child’s life.

Three of the six genes marked in the study are regulated by “neuronal activity” – doing, feeling, thinking – which in theory, suggests that altering the experiences of autistic children could help to change the course of the disorder. #