Deletion mutations in the dystrophin gene of Saudi patients with Duchenne and Becker muscular dystrophy

OBJECTIVE: The deletion in the dystrophin gene has been reported for many ethnic groups, but until now the mutations in this gene have not been thoroughly investigated in Saudi patients with Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD). We examined the deletion pattern in the dystrophin gene of the Saudi patients applying multiplex-polymerase chain reaction (PCR). The aim of this study is to describe the outcome of our initial effort to identify mutations in the dystrophin gene in a representative group of Saudi patients with DMD and BMD.

METHODS: Genomic deoxyribose nucleic acid was isolated from 41 patients with DMD and BMD (27 patients confirmed by muscle biopsy and 14 patients with clinical suspicion), 3 patients with limb girdle muscular dystrophy, 12 male relatives of the patients, and 5 healthy Saudi volunteers. A total of 25 exons around the deletion prone regions (hot spots) of the dystrophin gene were amplified. The study was carried out at the King Fahad National Guard Hospital, Riyadh, Kingdom of Saudi Arabia between 2000 and 2002.

RESULTS: The deletion of one or more exons was found in 21 of 27 DMD and BMD patients confirmed by muscle biopsy. The deletion in the gene was detected in 5 of 14 patients with DMD diagnosis, but not confirmed by dystrophin staining of muscle biopsy. No deletion in the dystrophin gene was detected in control Saudi volunteers, the limb girdle dystrophy patients, and the relatives of patients, as expected.

CONCLUSION: The present study suggests that intragenic dystrophin gene deletions occur with the same frequency in Saudi patients compared with other ethnic groups. The PCR-based deletion analysis provides a reasonable first step in the diagnostic care of Saudi patients who may be afflicted with DMD and BMD.