Researchers at Harvard University and Children's Hospital Boston will sequence the genomes of at least 85 people diagnosed with autism in a bid to tease out the genetic basis for some cases of the neuropsychiatric disorder.
Funded by $4.5 million from the federal stimulus package, the study's broad outlines were unveiled Wednesday.
The study's first phase will focus on 85 autistic patients from the Middle East. All have a recessive form of the disease, and all are linked by common ancestry. Studying this unique population, researchers have already narrowed the hunt for the common genetic mutation they share to an area that represents just 1% of their genome.
The Boston researchers hope to extend their genomic analyses beyond the 85 Middle Easterners to include American families as they refine their gene-hunting techniques. An "informatics" lab at Children's Hospital Boston will compare the genetic profiles culled from autistic subjects to stored genetic data on normal, healthy controls in order to find a needle -- or needles -- in a haystack: any genetic variations that might cause or boost the risk of autism.
Autism affects roughly one in 150 children, according to the Centers for Disease Control and Prevention. But many researchers and activists believe the disorder is becoming more prevalent, and the cause of that growth has sparked heated debate across the country. The condition frequently runs in families, and scientists consider it the most heritable of the neuropsychiatric disorders.
Still, studies of autism in the population find that genes can account for no more than 15% of the numbers of autism cases seen.
The rest are as yet unexplained. Many argue that environmental exposures -- in particular, to preservatives used in certain vaccines -- are a key factor in the development of autism. But a wide range of comprehensive investigations has failed to find such a link.
-- Melissa Healy