Can mutants age?

It’s pretty clear why Mystique didn’t age – it’s explained in First Class. And we already knew that – even if it’s the simplest of all explanations, her mutation allows her to age more slowly than others. Besides, why would a shape shifter choose to look old when staying forever young is a possibility?
But this is just Mystique. And, as we see, not all mutants have this regenerative ability – case in point, the younger versions of the first X-Men trilogy movies. This being said, and having the Days of Future Past characters in mind, why don’t they age?
This might seem a small detail. However, at times, it can pull you out of the movie. But I guess this is what happens when a shared universe is rebooted and in which the same characters are being used. And I guess this happens when the timeline is entirely messed up via time-travel.
Just check out Havok and his parents (who are also Cyclops’ parents). Bedazzling.
Speaking of which…
