My Daughter was diagnosed at 13 with Asperger's, she did get Dyslexia, ADD, NVLD and Bi Polar before Asperger's was finally diagnosed and she has all of this issues. My youngest was diagnosed with Asperger's at age 3 and my brother was diagnosed at age 42.
Only my youngest has had anger issues, read Tony Attwoods books they are good at explaining to parents and teachers the Rumble - Rage - Recovery stages of Asperger Rages. My boy went on Tofranil to help with the anxiety and then we taught him the internal identifiers that lead up to the rage, put in place a school strategy team that taught the teachers his triggers, and behavior's that identify his Rumble. Taught the teachers their roll in helping defuse the Rumble eg. time out in the library or on the computer to help calm him. Taught the teachers their roll in managing the Rage if they didn't defuse it and what they should of done differently the next time he Rumbles. The Recovery stage is very very important, NO ONE should be hassling him whilst he is coming down from a Rage, questions about his behavior, angry tones of voice etc can and will send him back into a Rage.
You should get busy becoming an expert on Asperger and what that means for your child, do not expect the education system to understand him, YOU have to educate them. Your son is not in control of his emotions and he needs to be taught how to control the internal feelings so that he doesn't lose control and hurt himself, others or property. It's goinging to get worse before it gets better, don't give up, be strong!!!
If he's on meds for ADHD or ODD they are wrong for him, they need to target the anxiety that is the underlying issue, teach him what his brain is not automatically able to do. He can not be held accountable for a behavioral reaction that he has no control of. A child that can not walk is not responsible for their inability to play touch football, well he is not responsible for his inability to control his emotions and needs the people around him to make the neccessary accommodations for him to be able to function at his best.
Now for some good news, my daughter is a fully qualified pastry chef, highly paid and highly regarded for her skills. My son no longer Rages because he has control of the emotions that he once didn't understand, the school have learnt to accommodate his needs and he is achieving accademically in all areas, if fact he was recently re-assessed as Gifted and no longer fiting the criteria for Asperger's, he's about to turn 10. If you put the hard work in now, then there is no end to what your child can and will accomplish, just never give up.
Janice