Myasthenia gravis (MG) is an autoimmune disorder caused by autoantibodies and related to the muscle nicotinic acetylcholine receptor (AChR) or muscle-specific tyrosine kinase (MuSK). Myasthenia gravis with anti-MuSK antibodies rarely occurs in children. The present article reports a childhood onset case of auto-immune MG with anti-MuSK antibodies, part of autoimmune polyglandular syndrome. (C) 2014 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.