Yes sometimes you will get a random white to yellow to yellowish-white plant, and sometimes you'll get a variegated one that is a combination of white/green or yellow/green. I'm sure it is due to some genetic malfunction. I only see one plant like this maybe every 4 or 5 years, so I don't think it is a really common thing. Well, maybe it is for people who grow acres and acres of corn more so than for the typical home gardener with a smaller plot.

There's even a variegated green-white-pink Japanese Maize that is grown as an ornamental plant. I've grown it and it is really quite beautiful, though if I am devoting space to corn, I want to get corn to eat, not just pretty foliage.