Hope raised for reversing severe childhood disease

By Will Dunham

WASHINGTON (Reuters) - Scientists searching for a way to treat the rare but severe childhood neurological disorder Rett syndrome have reversed the disease in mice, raising hopes for doing the same in people.

In a study appearing on Thursday in the journal Science, researchers led by Adrian Bird of the University of Edinburgh in Scotland switched on a gene called MECP2 in mice with the equivalent of Rett syndrome to make their symptoms vanish.

The surprising results contradicted the notion that damage to the brain caused by the disease, which occurs nearly exclusively in girls, is permanent.

"It rocked us back on our heels because in a way we were expecting a more disappointing result," Bird said in an interview.

About one in every 10,000 to 15,000 girls born have Rett syndrome, which affects all racial and ethnic groups worldwide, according to the U.S. National Institutes of Health.

In their first six to 18 months of life, the children develop apparently normally before the onset of devastating symptoms. Children with Rett syndrome commonly show autistic-like behaviors in the early stages.

It destroys speech, normal movement and functional hand use, and causes breathing difficulties, susceptibility to epileptic fits and tremors like those in Parkinson's disease. Many patients are confined to wheelchairs. Those who can walk do so with an abnormal, stiff-legged gait.

The disease, first described by an Austrian doctor in 1966, is caused by mutations in the MECP2 gene.