Temas please don't despair or get hung up on getting some sort of diagnosis. Schools are not necessarily the best place for all children. Some children just don't fit. Imagine if you had to go to work every day in a place filled with people you don't particularly like doing something you hated, you'd want to change and you would probably call in sick. Yet children are expected to conform and most do. I agree about home schooling, it might help, particularly if he is allowed to develop and acheive in his maths, but if he sometimes resists remember he's a teenager. I would also look at places of further education locally which offer courses he might enjoy. He's a bit young to go yet but they might take him at 15. His parents should open communications now. If he has some special interest he may be prepared to take that up. I would also look at youth organisations if he could be persuaded to join something for the social contacts. I'd recommend The Woodcraft folk which sounds terribly crafty but actually they have great provisions for children who are a bit different. woodcraft.org.uk
As I say don't despair. I have real experience and education between 12 and 16 isn't essential. A child can achieve, it takes a bit longer and needs them to work hard when they are older, but if you offer them support they can do great things. DS has 2 degrees, BA and MA which prove it.