Duchenne or Becker muscular dystrophy: A clinical, genetic and immunohistochemical study in China

Background and Objective: Duchenne and Becker muscular dystrophies are X-linked diseases caused by mutations in the dystrophin gene, which affect approximately I in 3,500 and I in 18,000 boys, respectively. The aim of this work was to develop a method to assist the diagnosis and classification of the disease. Materials and Methods: A large data set of dystrophin mutations was detected in 167 Chinese patients by multiplex ligation-dependent probe amplification and sequencing. Muscle biopsy, immunohistochemistry and STR analysis were also carried out in the patients and carriers. Results: One hundred and three deletions, 23 duplications and two-point mutations. The deletion of one or more exons was detected in 103 (61.7%) patients. The region spanning exons 44-55 was the most frequent deletion. The duplication was identified in 23 (13.8%) patients, which was more common than previously reported. Most duplications were found in exons 2-18. Six out of the 45 muscle biopsies analyzed showed the presence of other muscle diseases. Conclusions: This study may be important to enable comparisons of mutation type and the most appropriate analytical approach for samples from different geographical areas and ethnicities.