The authors concurr that while each episode of ON in MOG-IgG results in less optic nerve damage than single episodes of AQP4-IgG ON, the final deficits over time are comparable to those in AQP4-IgG ON, due to damage accrual driven by a higher relapse rate in MOG-IgG disease [21]. This evidence concerns the gene AQP4 and glycogen storage disease VI.