How is that even possible? Curing the effects of one mutation by adding another mutation doesn't seem logical, do they share the same locus? How would that even work?
Honestly, how it works or why, I really don't have an answer. I would think it would be entirely impossible... I'm still skeptical, only sharing what I know...
And yes, what I said referred the two genes being in the same gene locus... How? Why? I don't know.