I don’t think it was so much the mutant genes getting shoved into a poor bastard as much as simply the transference of energy of all the mutants who lost their mutancy. The story about that is in the New Avengers: The Collective TPB. I don’t think it’s very good, though. Probably the weakest thing Bendis has ever written, and the shoddy art doesn’t help.
That whole notion about the energy that resulted from the world’s mutants losing their powers has also led to a major story in the X-Men books. It starts with the story X-Men: Deadly Genesis and continues through Brubaker’s Uncanny X-Men run. That’s actually an excellent read.
There was one other story that had its genesis in the “No More Mutants” energy as well. I think it was Jeph Loeb’s and Rob Liefeld’s Onslaught Reborn miniseries. This one is probably the most essential and influential comic book ever crafted in the entire history of sequential, pictorial storytelling - it makes ancient Mayan hieroglyphs look completely useless. If you read Onslaught Reborn, I don’t think you’ll ever have to read anything ever again because, quite simply, it is the sum of all enlightenment.