Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are common X-chromosomal disorders frequently caused by genomic rearrangements. Using the novel multiplex ligation-dependent probe amplification (MLPA) method for genomic quantification of all 79 DMD exons we performed a retrospective analysis on 133 unrelated DMD/BMD patients, already screened for deletions in the hot spot regions using modified multiplex PCR kits.

MLPA-screening confirmed the presence of all deletions detected by multiplex PCR. Previously undetected deletions were found in six reinvestigated cases. In addition we found nine previously unrecognised duplications, dispersed over the whole gene. We also detected one point mutation, and  were able to precisely determine the breakpoints of all rearrangements (21 were unknown from the previous study). Overall, unrelated patients from Serbia and Montenegro contained 64% deletions and 7% duplications, figures not significantly different from other studies. In two brothers we identified a complex rearrangement involving two duplications and a triplication.

We conclude that MLPA is a highly sensitive alternative to multiplex PCR and should be considered as the method of choice for a first DNA analysis of DMD/BMD patients.