Also see specialisms WITHIN Autism that are different to the mainstream Autism
The one I know most about is
PDA: Pathological Demand Avoidance [1]
PDA presents differently and needs very different strategies to mainstream Autism.
Main signs… kids under 12 attend school. However they explode at home or in private. At school the PDAers are masking (pretending to fit in) which is draining. When they get home the pent up frustration is released (explosively). So the family at home see a very different kid to the one that school/extended family witness. If this is an A-Ha! lightbulb moment for you or your child, see the questionnaire at the PDA Society[1]
Is it due to stimulous overload or anxiety? I think that's the difference.
The point being misdiagnosis ocd as pda is a risk if autism is the only thing people consider. Maybe not a a huge deal since realistically a misdiagnosis often means you get a pamphlet with broadly similar advice and maybe and cbt anyway ... but maybe I'm being overly cycnical.