The present disclosure relates to a MTMR2-S polypeptide, or a nucleic acid sequence producing or encoding said MTMR2-S polypeptide, for a use in the treatment of a disease or disorder associated with MTM1 mutation or deficiency. The present invention provides compositions and methods for treatment of myopathy or diseases or disorders associated with MTM1 mutation or deficiency, in a subject in need thereof. The present invention relates to a method of delivering the MTMR2-S polypeptide to subjects in need of improved muscle function, such as subjects with centronuclear myopathies.