I've been doing some more research and I found that there was a study done on some people that had autism, post mortem. They dissected their brains and it turns out that we have on average 67% more neurons than people without. So, I would say that you could safely say that Einstein had autism. When they dissected his brain this is what they concluded:
"Alterations in cortical thickness and neuronal density in the frontal cortex of Albert Einstein" was published in 1996. Because Einstein's brain weighed only 1,230 grams (1,400g is average for a man) and his cerebral cortex was thinner than usual, the scientists concluded that Einstein's brain had a much greater density of neurons.
Given this information, his unusual behavior and social ineptness, I'm adding him to the list. If you don't like it...
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Attending that there is not any neurological test to diagnose living people with autism, I doubt that a post-mortem exam could do that. The only thing that you can conclude form these examination is that Einstein has an abnormal neurology, but probably almost all excentric people (autistic or not) have abnormal neurologies (btw, Einstein had a schizophrenic son).