Girls with Rett syndrome appear normal after birth. From age 6 months to age 18 months, they gradually lose speech and motor skills. Later, they develop autism-type symptoms, such as repetitive movements, epilepsy and social withdrawal. There is a very real chance that understanding the genes would lead to treatment. Many autistic people also are mentally retarded.
Scientists believe that autism is a biological disorder at least partly caused by genes.
Autism and autismlike disorders affect about 400,000 people in the USA, according to the Autism Society of America. The explosion in genetic research in autism includes ongoing studies of chromosomes 7 and 15, where the genes for autism are suspected to reside. Genetic researchers also are studying families of people with autism. Twelve studies around the USA are being conducted on secretin, a hormone that has been shown to improve language and cognitive abilities in some people with autism. The Senate heard testimony on S. 512 last month.