In a paper published today in The New England Journal of Medicine, researchers have identified a segment containing 25 genes on chromosome 16 that was deleted or duplicated in roughly one percent of children with autism.

Donald T. was not like other 5-year-old boys. Leo Kanner knew that the moment he read the 33-page letter from Donaldʼs father that described the boy in obsessive detail as “happiest when he was alone… drawing into a shell and living within himself… oblivious to everything around him.”