GJA1 and myeloid sarcoma: Six of nine MS and NMO/NMOSD cases with extensive Cx43 loss classified as pattern A or B died within two years, while none of eight other patients without Cx43 loss had such a rapidly progressive course; death frequency within two years after disease onset was significantly higher in cases with extensive Cx43 loss compared with cases with no Cx43 loss (66.7% vs. 0%, P = 0.0090) (Table 10).