Researchers have identified what they say is a rare but potentially treatable form of autism.
It stems from a gene that controls the breakdown of certain proteins, known as branched chained amino acids. The proteins are important in brain chemistry and must be gotten from food, since the body can’t produce them.
In most people, the gene slows down the metabolism of the proteins to maintain an available supply in the blood plasma. But certain mutations in the gene deactivate it, so the proteins get broken down too rapidly.
The result, researchers reported Thursday in the online issue of Science, is a severe form of autism whose symptoms include not only social and communication deficits — the hallmarks of the disorder — but also epilepsy and mental retardation.
It’s an encouraging finding, because it suggests a simple treatment: Eating more branched chain amino acids, a nutritional supplement available at health food stores. Indeed, in mice engineered with a mutation in the same gene, symptoms could be controlled by changing their diet.
The next step is to study the treatment in people with the mutations, which are inherited.
Now for the bad news: The discovery is unlikely to be of much direct benefit to the vast majority of people with autism, a disorder so diverse that many scientists believe it actually has many distinct biological causes.
The mutations in this study are thought to be extremely rare, accounting for a tiny portion of autism cases.
The discovery grew out efforts at UC San Diego and Yale to sequence portions of DNA in patients with autism. The mutations were discovered in two children — one with Turkish ancestry and the other with Egyptian roots.
You can read a summary of the study here.
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