Progressive myotonic dystrophy is characterized by progressively increasing muscle weakness and atrophy as the main clinical manifestation. Due to different genetic defects, clinical symptoms appear as early as fetal life and as late as adult onset, and progress at different rates. Commonly used tests: ①Creatine phosphokinase (CK): significantly elevated. Significant elevations can occur in the asymptomatic phase. ②Electromyography: myogenic damage. Dystrophin immunohistochemical staining was negative. DMD gene examination: The DMD gene is one of the more massive genes in humans, including 79 exons. Types of gene mutations include deletions, duplications, and point mutations. About 65% of Duchenne muscular dystrophy and about 85% of Becker-type muscular dystrophy are caused by deletion of one or more exons of the DMD gene; 6-10% of Duchenne and Becker muscular dystrophy are caused by duplication of one or more exons of the DMD gene. Classical multiplex PCR techniques can detect approximately 98% of gene deletions. MLPA (multiplex ligation-dependent probe amplification) is currently the most commonly used method for the detection of all exon deletions and duplications. ⑤ Echocardiography and ECG: Children should be evaluated regularly for cardiac function, including echocardiography and ECG.