The natural history of the patients with Duchenne muscular dystrophy in Taiwan: A medical center experience

Abstract

Background: Duchenne muscular dystrophy (DMD) is the most common hereditary muscular dystrophy and caused by DMD gene mutation. In addition to progressive proximal muscle weakness, respiratory, orthopedic, and gastrointestinal complications are often observed in DMD. The natural history of patients with DMD in Taiwan has not been reported thus far. Methods: Medical records of 39 patients who received a diagnosis of DMD between 1999 and 2016 at Kaohsiung Medical University Hospital were reviewed. The diagnosis of DMD was confirmed through muscle biopsy or DMD genetic analysis. Results: The mean onset age and mean follow-up period were 2.75 years and 6.76 years, respectively. Seventeen patients (43.5%) had a family history of DMD. The mean full intelligence quotient of the patients was 71.08, and the mean age of walking ability loss was 9.7 years (25 patients). The mean onset age of respiratory insufficiency was 10.64 years with a decline rate of 5.18% per year (25 patients). The mean onset age of cardiomyopathy was 14.69 years (seven patients). The mean onset age of scoliosis was 13.29 years with a progression rate of 11.48° per year (14 patients).Eleven (28.2%) and eight (20.5%) patients had deletions and duplications of DMD, respectively. Fourteen patients (35.9%) had point mutations or small deletions or insertions. Five patients received only multiplex ligation-dependent probe amplification (MLPA) analysis and exhibited neither deletion nor duplication. No mutation was identified in one patient through both MLPA and exon sequencing. Conclusion: The clinical phenotypes and disease course in our cohort were consistent with that reported in previous studies. However, the proportion of point mutations or small deletions or insertions in our study was considerably higher than that in reports from other populations. Cardiac ejection fraction was found not a reliable biomarker for identifying cardiac problems, discovering a better parameter is necessary. Key Words: corticosteroid, Duchenne muscular dystrophy, natural history, Taiwan