Diagnosis of becker muscular dystrophy: Results of Re-analysis of DNA samples

Introduction: The phenotype of Becker muscular dystrophy (BMD) is highly variable, and the disease may be underdiagnosed. We searched for new mutations in the DMD gene in a cohort of previously undiagnosed patients who had been referred in the period 1985-1995. Methods: All requests for DNA analysis of the DMD gene in probands with suspected BMD were re-evaluated. If the phenotype was compatible with BMD, and no deletions or duplications were detected, DNA samples were screened for small mutations. Results: In 79 of 185 referrals, no mutation was found. Analysis could be performed on 31 DNA samples. Seven different mutations, including 3 novel ones, were found. Long-term clinical follow-up is described. Conclusions: Refining DNA analysis in previously undiagnosed cases can identify mutations in the DMD gene and provide genetic diagnosis of BMD. A delayed diagnosis can still be valuable for the proband or the relatives of BMD patients.