MOG and optic neuritis: Among native-MOG Ab+ children, ADEM was the most prevalent phenotype (38%, 53/139), and most exhibited a monophasic course (79%, 42/53) (Table 1, Fig. 1d), whereas in adults, optic neuritis (ON) was most common (61%, 91/148), and most presented with relapsing unilateral ON (UON) (27%, 25/91).