Clear Light of Day. Story of two sisters. One character, their brother, is autistic. Science Fiction book that includes a young autistic character. A reader says Dick gained his knowledge when he babysat a ten year old with autism.
Reader describes one character as autistic.
I think the character persists in the series and in a followup series The Malloreon. Faulkner's first major novel. One character, Benji, appears to be autistic. Part of the series New juvenile series on the exceptional child. The book was very popular in the past before being re-released due to interest.