So in my previous job I worked at a science lab and worked with many individuals who has asperger's syndrome. I'm no professional, but it does seem like it's a "thing" amongst scientists. Although I understand that everyone is different, I think what I learned from my interactions is that they are wired differently than us. What seem to be an obvious and normal interaction between peers, family, or friends is not as obvious or normal to them. However, this also means that you can just tell things directly, and not worry about the consequences (ie. offending them).

An example : I told a senior scientist that he smells like he hasn't showered in days so he should wash up. He just took it, and the next day, he made it a point to come up to me to report that he had showered!

Sure maybe everyone is different, but I have this gut feeling that you can take the silver lining of the aspergers and use it to your advantage. I think you can probably visit your brother, tell him face to face that it was not appropriate for him to throw his family member out of his house because of his own obsessive habits and that you are unhappy about it. He may not be cued in to realize that he should apologize, but at least he will know where you stand.

I think there's only so much you can expect. None of these scientists I speak of have wives or close friends, but they are outstanding in their jobs because they are so hard working and so detail oriented.