1 Autism Disorder (Rett) Reversible?
Mouse Study Shows Rett Syndrome -- a Devastating Autism Spectrum Disorder -- May Be Curable
Rett Syndrome: A Devastating Autism Spectrum Disorder
Rett syndrome is part of the spectrum of autism disorders.
Symptoms usually appear at age 6 to 18 months. As in other autism spectrum disorders, children withdraw socially. Like Chelsea, they often cry -- for months on end.
Unlike kids with other autism disorders, Rett-syndrome children often begin constant, compulsive hand wringing. They lose any language and motor skills they may have learned.
Eventually, their hands become useless, as the ability to organize voluntary movements goes away. Chewing, swallowing, and even breathing can be a problem. Tremors are common; some kids have seizures.
The gene responsible for Rett syndrome appears only on the X chromosome.
Boys have only one X chromosome. If they inherit a mutant MECP2 gene, they usually die as infants.
But girls have two X chromosomes. If they inherit the mutant gene from one parent, they almost always get a good copy of the gene from the other parent. X-gene expression is random in females, so girls with a single copy of the gene still have some MECP2 gene function.
That rescues girls from death. "But the price of the rescue is Rett syndrome," Bird says.
Today, Chelsea is confined to a wheelchair. She must be tube-fed. She cannot use her hands or make any purposeful movements, and she suffers daily seizures.
But Coenraads says Chelsea also "is a social, affectionate, loving child who has incredible patience and wisdom beyond her years."
Now Coenraads can hope that she'll one day see Chelsea recover from the illness that imprisons her.
Coenraads' hope is professional as well as personal. She's co-founder and director of research at the Rett Syndrome Research Foundation, which partially funded Bird's research.
"This raises the possibility that Rett syndrome and related postnatal disorders are reversible," Coenraads says. "It is extremely encouraging. This suggests there is no window of opportunity in which you have to act, so women who have suffered for years may get helped."
Also encouraging is the possibility of reversing other diseases that involve MECP2 mutations.
"We are only now getting a handle on how many conditions involve MECP2 mutations. Schizophrenia, movement disorders, mental retardation with seizures -- Rett syndrome is just scraping the tip of the iceberg," Coenraads says.