Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are the most frequent muscular dystrophies. Present study aimed to determine the frequency of dystrophin gene alterations in Iranian DMD/BMD patients using molecular techniques. 146 Iranian DMD/BMD patients have been analyzed using two devised sets of multiplex polymerase chain reaction (M-PCR) followed by multiple ligation-dependent probe amplification (MLPA). Two isolated DMD and BMD patients were analyzed by DNA sequencing. 30.9 % of patients had single-exon deletion while group and contiguous exon deletions were identified in 41 % of the patients. The most numerous exon deletions included exons 45-50 and were identified in the first M-PCR set. Deletion detection rate was 99 % in first M-PCR set and remaining deletions (1 %) were identified in the second M-PCR set. MLPA analysis showed that there were two exons 3-5 and 41-43 duplications (1.4 %) in a BMD and a DMD patient, respectively. Two nonsense mutations including c.633dupA and c.6283 C>T were, respectively, found in a DMD and BMD patient in which c.633dupA has not ever been reported in DMD mutation database and was pathogenic mutation. Besides the report of frequency of dystrophin gene alteration in a subset of Iranian DMD/BMD patients, it was revealed that the proposed M-PCR protocol can be useful in the initial step of molecular diagnosis of DMD/BMD. Exon sequencing would be the final step in determining the mutation status of DMD/BMD patients following MLPA.
Keywords: BMD; DMD; MLPA; Multiplex PCR; Mutation.