MuSK (MUSCLE SPECIFIC KINASE) ANTIBODY

Anti-muscle-specific kinase (anti-MuSK) antibodies are autoantibodies, proteins produce by the immune system that mistakenly attacks proteins called muscle-specific kinases. This test detects these autoantibodies in the blood of people with myasthenia gravis (MG), a rare but often severe autoimmune disease that causes muscle fatigue and weakness.

Muscle-specific kinases are proteins found where nerve endings and muscle fibers come together (neuromuscular junctions). Although the cause of MG is not fully understood, it is thought that the anti-MuSK antibodies interfere with the transmission of signals between nerves and muscles.