Factors that predict recurrence include: longitudinally extensive lesions in spinal cord, brain lesions on MRI, existence of one or more autoantibodies (ANA, ds DNA, phospholipid antibody, C-ANCA), underlying collagen vascular disease, OCBs in CSF, presence of NMO-IgG (anti-Aquaporin-4)antibody (27,50) and female sex (1). The gene discussed is AQP4; the disease is neuromyelitis optica.