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

Duchenne and Becker muscular dystrophies are X-linked diseases caused by mutations in the dystrophin gene, which affect approximately 1 in 3,500 and 1 in 18,000 boys, respectively. The aim of this work was to develop a method to assist the diagnosis and classification of the disease.

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.

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.

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.