Hmmm... if memory serves me right, there was a calico corn morph a few years back that was NOT genetic. It was actually like a virus that caused the scales to turn white and off textured. I believe the snakes with this affliction eventually died premature. Dont quote me on this!!! So, this piebald garter may actually be suffering from some sort of viral affliction causing the loss of color in the scales. Only way to prove genetically is through trial breedings.