Steinert disease, also known as myotonic dystrophy type 1, is a muscle disease characterized by myotonia and by multiorgan damage that combines various degrees of muscle weakness, arrhythmia and/or cardiac conduction disorders, cataract, endocrine damage, sleep disorders and baldness. The disease is myotonic dystrophy type 1 (MONDO_0008056). Also known as: DM1, DMPK myotonic dystrophy, MD1, Myotonic Dystrophy, Steinert disease, Steinert myotonic dystrophy syndrome, Steinert syndrome, dystrophia myotonica.