Another recent study also reported the existence of ethnicity based differences between Caucasians and African Americans with MG in the United States and identified ethnicity based differences in the rates of anti-AChR antibody positivity, anti-MuSK positivity, frequency of abnormalities on repetitive nerve stimulation results, and differences in rates of clinical severity, as well as gender based differences in age of onset [7]. Here, MUSK is linked to myasthenia gravis.