II think the age listed for symptoms is prob quite important.. and also the reason that CAHMS are usually reluctant to diagnose autism too early..because of the overlap.. however in my own experience working for years with ASD/SLD children there IS a difference and one which becomes more obvious over time. A child who showed very clear triad of impairments would be diagnosed as autistic earlier than one with the 'clumsy' dyspraxic symptoms prevalent .
Children with dyspraxia (excepting those with severe verbal dyspraxia) can usually be educated in mainstream with reasonable support... those with severe triad of impairments are unlikely to be maintainable in mainstream after the early years..but it's pretty impossible to know how a child will develop in the early years unless the difficulties are very severe.
With my own son the concerns were all physical initially.. didn't walk til 2.5 didn't speak til 4..couldn't do anything other kids his age could do..and wasn't interested in other children either..but gentle and passive.
Now 12 he is still motor impaired.. can't walk brilliantly (wears afos for poor muscle tone) speech slurred and hard to understand,can't do shoe laces, writing is like a 6 yr olds in content and appearance... but now what is going to make his adult life dependent isn't the dyspraxia, but the autism, because while he can now talk..he can't converse.. he's a computer with a one way download ability!!
If I were able to truly separate the two I'd say the autism is the more devastating on how it will impact his adult life..because the physical disability we can work round.. aids, afos, bottle openers.. but the autism will prevent him from ever being independent.
That doesn't mean that dyspraxia is mild or anything I hastily add... I hate both.. just trying to sort of describe how they are different in their impact and hence how they aren't the same thing
Clear as mud, me
I don't know anything about your situation of course.but if you have a little one with symptoms of both/either I'd push for as much phyio/OT input as poss..because the sooner the physical stuff is helped the easier it is to see what is causing what!