1 Autism Disorder (Rett) Reversible?
Mouse Study Shows Rett Syndrome -- a Devastating Autism Spectrum Disorder -- May Be Curable
Possible Rett Syndrome Treatments
Bird's study used mice genetically engineered to carry a MECP2 gene switched off by a genetic element called a stop cassette. These mice act just like humans with Rett syndrome -- their paws can't grasp and they can't walk. They also become obese, something not seen in human Rett patients.
The MECP2 stop cassette in the mice carries a kind of ejection button triggered by a drug. When mice are given the drug, the stop cassette is ejected and their MECP2 genes start working again.
If this is done slowly enough, the mice begin acting like normal mice.
Humans, of course, aren't genetically engineered to carry ejectable stop cassettes. This means that switching on MECP2 function isn't a simple matter.
Bird says there are three likely approaches to a Rett syndrome treatment.
One is a gene therapy that would give people a functional MECP2 gene. That's going to be especially tricky, as too much of this gene is as bad as too little. But gene therapy research may one day be able to solve the problem.
Another idea would be to take advantage of the fact that most females already carry a good MECP2 gene in every cell of their body. It's just that many of these genes are inactive.
"If you could reactivate that gene, it would be potentially fantastic," Bird says. "But we have no idea of how to get these silent genes to start working again."
And there may be a drug that could mimic the protein made by the MECP2 gene, or by the "downstream" genes that a normal MECP2 gene turns on and off.
"So instead of trying to fix the gene, you develop a drug that counteracts the secondary effects of it," Bird says.
Whatever the eventual treatment may be, Coenraads says it's going to take "a lot of research and an enormous amount of money" to find it.
The Bird team's new finding may well stimulate just such an effort.