I know just two families with autistic children. (not aspbergers, but autism itself)
One is my cousin who has quadruplets. He has Fraternal twin girls and Identical twin boys. The boys are autistic the girls are not. One boy is has a much more serious case of autism then the other. He doesn't connect with the world around him much.
The second family is my best friend. She has Identical twin girls. Both autistic, one more severe case then the other.