Patients with fever induced hearing loss regardless of OTOF mutations were specifically excluded (see inclusion criteria on clinical trials.gov for NCT05788536).

With regard to your point about shedding or systemic exposure. If non functional copies of OTOF in the other tissues expressing the gene were to be replaced by functional copies, what is the concern? How would that negatively impact patients? Doesn’t seem like this would/should be a concern.

Also, mutations don’t have to be teleologically beneficial to occur and persist. They can persist because they are not fatal nor do they impair reproductive competence.