Itachi killed his whole clan when he was very young, i'm not sure what age, but probably around 17. It's feasible that Naruto could become Hokage by the time he's 17. I'm thinkin he probably won't be just because there are so many other powerful jounin and chuunin in Konoha. I'm purely guessing that there will be 1 more Hokage before Naruto.