Might have picked up whatever it is from mom since enchi suppresses and cleans up the pattern a lot and pinstripe can hide it entirely sometimes. The first thing that comes to mind is trick/hurricane. I would not sell them as those without being absolutely sure after test breeding them though because sometimes normals can look like that, breed, and whatever is causing it doesn't show up in their hatchlings.
If the pattern really interests you, I would hold them back and do some test breeding. This can be a bit of a money suck starting off but if it proves out, it will be more than worth it.