Mutation or lighting?

Has anyone seen a plant develop a node like this before? On the third node it has complete ring of undeveloped leaves around the stem. The stem also looses about 50% of its diameter after the node. This is a 3 week old Rocket Fuel Auto on a 24 hour light cycle and the only plant to show it. I'm wondering if maybe the light was too close for it.

Well it was close enough by the appearance of this. Perhaps a little too close.