not sure why no one has answered your message.
I guess that not many people belong to this forum? not sure.
I got an email so thought I would reply to help
I think that you could very well be on the right track regarding your son.
Although please keep in mind I am not a medical professional but someone also with autism (Asperger syndrome).
Many of the symptoms that you have listed can be associated with Autism.
The jumpy limbs is often associated with Autism. Periodic limb movement disorder.
Although in my experience the limb movement disorder can also be caused by too much dopamine which can in turn be caused by a high dose of venlafaxine.
Perhaps only people with the disposition are affected? Not sure, cant say.
What you mention as tantrums, if autism related would not necessarily be tantrums in the naughty sense but overstimulation and lack of control over cognitive function that prevents overstimulation. If your son has autism then the tantrum thing will not be controllable although there may be things that can be done to reduce the chances of overstimulation happening.
I think that your best bet would be to find a specialist, as to be brutally honest. General practitioners are usually absolutely useless when it comes to autism especially where the patients IQ is normal or higher than normal.
The problem with doctors is that many of them think they know everything but don’t.
The problem with autism is that it is a neurological condition and disability that is invisible. it can not be diagnosed by how someone looks.
The additional problem is that previously people associated being retarded with autism. Autism is not a retardation but a neurological diversity or impairment.
I recommend that you seek out a clinical psychologist who has a specialism in diagnosing Autism Spectrum Disorder/Condition.
As a good experienced professional will be able to make a good assessment.
Hope this helps
the books by Tony Atwood are also useful for Asperger Syndrome.