I vote for classical autism.
I've just recently had a conversation that it is typical for autistic children to develop speech and then lose the already developed speech. That must all be before age... 3?
AS is usually defined as using language adequately between ages 2 and 3.
demoluca: Do you mean your brother could spell words before he had age-appropriate speech? Have you looked into a thing called 'hyperlexia' yet?
I'll check for an article in a sec and post it, if I still have it. (I'm not sure I can find it again?)
Edit: Not sure how reliable this article is.
http://www.hyperlexia.org/hyperlexia.htmlI'm not sure whether it mentions, but AS/classical seem possibly comorbid to hyperlexia.
But I think if your brother lost language it could be classical (kanner's) by definiton. Or, if a professional would think he's too hf or too atypical or too whatever to fit kanner's
or AS, then maybe he could have PDD-NOS. (If this diagnosis exists where you live.)
But in the end I'm so not a professional of course.
He started babbling and talking normal, stopped for a year when my dad went up north, and started again when my dad came back, only he kept spelling things.