Limb-girdle muscular dystrophy type 2B,a type of dysferlinopathy, is caused by mutations in the dysferlin gene (DYSE). It is characterized by predominant weakness and atrophy of muscles of the pelvic and shoulder girdles, massive elevation of serum CK concentration, slow progression, and onset usually within the second or third decade of life. We present a Chinese patient whose disease onset was at the age of 50 years with persistent elevation of transaminases for 3 years before weakness appeared. She had been considered as having liver disease for a long time and then polymyositis. Finally, biceps brachii biopsy revealed dystrophic morphology and depletion of dysferlin in immunohistochemistry. This case should remind readers that late-age onset of dysferlinopathy can be misdiagnosed as liver disease or polymyositis.