Issie
I am sorry but you cannot assume this. There are no conditions that automatically entitle a claimant to ESA.
Like any condition, Aspergers, can affect a sufferer in a wide variety of ways, in some cases there may be little impact in others it may be severe.
Unfortunately the Exceptional Circumstances, always require the claimant to prove their case, so you will need to provide compelling evidence that this would be the case for your son.
Have a look at our ESA Claim guides on the following link.
www.benefitsandwork.co.uk/help-for-claimants/esa Good luck
Gordon