However, the youngest patient in this cohort was just 6 years of age at onset and the oldest experienced his first attack at age 70, suggesting that MOG-IgG-positive ON and/or myelitis – just like AQP4-IgG-positive NMOSD [34] – can occur irrespective of age and need to be considered also in children and in the elderly. The gene discussed is AQP4; the disease is myelitis.