LRP4 and myalgic encephalomeyelitis/chronic fatigue syndrome: All ME/CFS patients tested negative for MG-specific autoantibodies, while only 6% to 10% of MG patients have negative results on standard assays for AChR, MuSK, and LRP4 antibodies, referred to as having “seronegative MG.” While patients with seronegative MG are more likely to present with primarily ocular symptoms, they generally share similar features as those with seropositive MG (Deymeer et al., 2007).