definitely a genetic mutation. Most plants carry these genes, and almost every plant Ive ever grown has thrown out an expression of a mutated gene at least once in its lifetime. Case in point,
The OP has a gene that is quite strongly being expressed in a physical way. In the case of my plant, it is simply popping out very very randomly.
I have noted this phenomenon on almost every plant Ive ever grown. It may come in the most usual form like a leaf with 3 fingers where 7 should be? Or a branch growing out of a leaf stem. Most if the time these go unnoticed because there are so many leaves.
A fairly common mutation is a bud growing on a leaf or self topping plants.