[kbelder]

I'm pretty ignorant in this field.

Does gene therapy treatment correct the issue just in the individual, or does it also correct the genes inherited by the individual's children?

[KingMob]

This particular treatment only applies inside the ear, afaik, but it's theoretically possible to apply gene therapies to rewrite more cells, for more systemic diseases.

That might also suffice for sperm, which are constantly being created anew, but I'm not sure that would work for eggs, which are largely formed in gestation. But there might be an egg-specific variant treatment.