Hmm, this issue bring up some really interesting points about the Sharingan. I'm still under the firm belief that the Magenkyou can only be performed when an individual has two working Sharingan eyes and is an Uchiha. The former because the Magenkyou seem to relate to how many dots each Sharingan eye can generate the latter because I doubt someone who is not a Uchiha can survive the output of Chakra to the Sharingan. The Uchiha, for lack of a better word, seem to be made to wield the Sharingan. Their bodies (or at least their eyes) seem to be able to stand the generated Chakra without too many detriments (unlike Kakashi whose body need much rest after using the Sharingan. Sasuke had used it for much longer periods of time without needing prolonged bed rest.) Though this brings up the interesting point of Itachi, I'm sure at on point someone made the remark that using the Sharingan (or was it the Magenkyou?) plays havoc on ones health.

See, this is when I wish I know more about genetics.