Autism gene search turns hope of treatment. WASHINGTON (Reuters) - A group of researchers who studied more than 100 families prone to autism said they identified at least six new genes that seem to underlie the disorder and that it would be possible to treat at times.
The research, published in the journal Science, reinforces the popular belief that autism is a disease of single origin but may be caused by several genetic and environmental factors.
The study also showed that, at least in many of the families studied, autism appears to be caused by a combination of faulty DNA and something in the physical or social environment affected child after birth.
mutations appear to disrupt genes important for brain development, which are activated and deactivated by the activity of brain cells called neurons, which are stimulated by early childhood experiences.
"seem to be many different mutations involved and each family would have a different genetic cause, "he said in a statement Dr. Thomas Insel, director of the National Institute of Mental Health, which helped fund the study.
" The unifying observation from this new report is that all the relevant mutations could damage the formation vital neural connections during a critical period in which experience shapes the developing brain, "Insel said.
Doctors Christopher Walsh and Eric Morrow of Harvard Medical School in Boston, and colleagues studied 104 families in U.S., Pakistan, Turkey, Jordan, Saudi Arabia and Kuwait.
All participants had family members with autism and 88 families were common in marriages between cousins.
Such consanguineous marriages can do most common disorders requiring two defective copies of a gene to occur.
"Marriages between first cousins \u200b\u200bincreases the prevalence of neurological birth defects by about 100 percent," they said. EARLY EXPERIENCES
"Autism symptoms emerge at an age in which the developing brain is refining the connections between neurons in response to the childhood experience," said Walsh.
"If certain important genes are activated or not depends, therefore, neural activity driven by the experience. The loss of the refining process would be a common mechanism of mutations associated with autism, "he added.
a finding that offers some hope is that many of the variations were caused by missing or damaged genes, but simply because they are disabled.
" That means we would not need replacing the gene, if we could figure out how to reactivate it, perhaps with medication, "said Morrow ..
Autism, characterized by poor social interaction and communication, or related disorders such as Asperger syndrome, affect about one in 150 children in the United States, according to estimates by the Centers for Disease Control and Prevention (CDC).
Autism can cause mental retardation in up to 70 percent and seizures in 20 to 25 percent of cases.
