it is mentioned in Mutant/Human ethics Class by Charles "what if we could say transfer one person's consciousness into the body of another, eluding to Charle's powers AND the fact that he transferred his Mind into the body of his Twin who in the comics was born with ZERO higher brain function but was non the less fully alive. Charle's Gift that he developed was entering his twin's mind thus trnsfering his conscienceness into his twin.

It is mentioned in Mutant/Human ethics class by Charles, "What if we could, say, transfer one person's consciousness into the body of another?" alluding to Charles's powers AND the fact that he transferred his mind into the body of his twin who in the comics was born with ZERO higher brain function but was nontheless fully alive. Charles's Gift that he developed was entering his twin's mind thus transferring his consciousness into his twin.