My younger brother has ADHD and Aspergers and he is particularly gifted in the area of mechanics and electronics. He started taking plugs apart at 2 and moved on to larger machines as he got older. He is now 18 and an apprentice mechanic who is brilliant at what he does.
However, his intellectual and social development is very lacking. He is the opposite to me, where I developed intellectually and artistically, with very little skill in maths, science or electronics. I'm not sure if he is an "indigo child" but he certainly is like no other ordinary person his age.