A pattern of gene activity in the language and decision-making centers of the human brain is missing in Fragile X syndrome, a disorder associated with autism and learning disabilities, according to a study by Yale researchers published in the May 11 issue of the journal Cell.
The researchers identified evolutionary changes that led the gene NOS1 to become active and produce a protein product in the parts of the developing brain that form the centers for those higher functions in adults. A protein that controls this activity is missing in Fragile X syndrome, the leading inherited form of intellectual disability among boys and the most common single-gene cause of autism. People with Fragile X syndrome have lower IQs, a high rate of attention-deficit/hyperactivity disorder, and delays in speech and language development.
“The same evolutionary mechanisms that may have gifted our species with amazing cognitive abilities have also made us more susceptible to psychiatric disorders such as autism,” said senior author Nenad Sestan, M.D., Ph.D. ’99, professor of neurobiology.