So many different populations of people have sensory integrations problems, that this is not a very specific ASD characteristic. Neurotypical kids with learning disabilities, mental retardation, giftedness, ADHD, Tourette's, OCD, etc., all commonly have problems with sensory integration. Not to mention that there are neurotypical kids without any other kind of syndrome who have sensory integration dysfunction. It is just not specific enough, so it wouldn't have the same diagnostic usefulness as the current criteria. It's just doesn't discriminate ASD from other conditions as well as say, "qualitative impairment in social interaction."
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Not all those who wander are lost... but I generally am.