Deletion patterns in Argentine patients with Duchenne and Becker muscular dystrophy

The identification of mutations in Duchenne or Becker muscular dystrophy (DMD/BMD) patients is important for carrier detection in these families. We present the patterns of deletions of the dystrophin gene in Argentine population. DNA from 75 patients with DMD/BMD was analyzed by multiplex PCR and, in some cases, cDNA/Southern. Deletions were detected in 24 patients (32%) and were mainly clustered in two areas of the dystrophin gene: the 5' end (exons 3-12) and the central part (exons 44-53). 64% of the deletion endpoints lay in the middle region and 34% in the 5' end of the gene. The most frequent sites for deletion-endpoints were in the introns 47 (13.6%), 44 (11%), 2 (9%) and 12 (7%). Thus, the proportion and distribution of deletions in our DMD/BMD patients differ from those reported for other populations. Furthermore, a higher proportion of deletions was observed in familial cases (40%) than in isolated ones (30%), in contrast to previously reported data. The effect of the deletion on the reading frame agree with the phenotype in almost all the patients studied. This study will be useful in prenatal diagnosis and diagnosis of other Argentine DMD patients.