Approximately 25–30% of children with autism spectrum disorders stop speaking after beginning to say words, often before the age of two.[4]
According to Ami Klin, "Most examples of autistic regression...are based upon a child's loss of a handful of words...it's possible that these children were only echoing sounds they heard from their parents"[5]
The temporarily acquired skills typically amount to a few words of spoken language, and may include some rudimentary social perception