Compared with the nonoverlapping syndrome group, the GFAP-AQP4 group had a higher proportion of women (88.9% vs. 32.3%, p = 0.004), lower CSF white blood cell counts (median: 31 cells/mm3 vs. 94 cells/mm3, p = 0.011) and protein levels (median: 0.368 g/L vs. 0.78 g/L, p < 0.001), and a greater proportion of patients receiving long-term immunotherapy (77.8% vs. 13.8%, p < 0.001) (Table 3). Here, AQP4 is linked to Down syndrome.