Chinese scientists have created monkeys with a version of autism that could eventually help in the cure for this complex spectrum of brain disorders that affects millions of children worldwide. Autism has been identified in approximately 1 in 68 children in the U.S., and its characteristics are only now becoming better known.

Although the Chinese scientists' breakthrough is significant, it also raises some practical and ethical questions. Rett Syndrome is a rare genetic disorder that causes many of the symptoms of autism. Ninety percent of patients with this disorder have a mutation in a gene called MeCP2. Duplicate copies of this gene produce the kind of autism known as MeCP2 duplication syndrome. Although scientists had previously created this kind of autism in mice, their brains, unlike the brains of monkeys, are much simpler than humans' and don't show many of the developmental and behavioral problems that humans manifest. Now, for the first time, Chinese scientists have created monkeys whose DNA has been genetically altered to make them develop a type of autism similar to that found in humans.

The creation of these "transgenic" monkeys, reported in the journal Nature, offers a good model for studying and understanding human brain disorders such as autism.