"We made these mice so that we can turn the genes on and off as we want," Washbourne said. "Using an antibiotic, doxycycline, it turns off these altered genes that we inserted into their chromosomes. While on doxycycline, the mice are absolutely normal."
However, if the inserted gene was turned off after the completion of development, mice still showed altered synapses and behavior. This result suggests that any kind of gene therapy may have to be applied to individuals with autism early on.
Effects seen in the social behavior of mice with the mutated gene, he said, are not unlike observations reported by parents of many autistic children. While normal mice prefer to engage with new mice entering their world rather than familiar others, or even a new inanimate object, these mice split their time equally. "It's not a deficit in memory regarding which mouse is which, it's more a weighting of their interaction. Does that mean they are autistic? I don't know, but if you talk to parents of autistic children, one of the frustrating things they report is that their children treat complete strangers in exactly the same way that they treat them."
While the findings provide new insights, Washbourne said, any translation into treatment could be decades away. "A problem with autism is there are many different genes potentially involved. It could be that some day, if you are diagnosed with autism, a mouth swab might allow for the identification of the exact gene that is mutated and allow for targeted therapy," he said. "Genome sequencing already has turned up subtle mutations in lots of genes. Autism might be like cancer, with hundreds of potential combinations of faulty gene
|Contact: Jim Barlow|
University of Oregon