Deletion patterns of dystrophin gene in Hungarian patients with Duchenne/Becker muscular dystrophies

Deletion pattern analysis of the dystrophin gene was performed in 159 Hunga rian patients with Duchenne/Becker muscular dystrophy. In 116 cases (73% of total patients), exon deletions were detected by PCR amplification, In 37 patients (31.9% of patients with a deletion) one exon was deleted, while fi ve or more exons were missing in 40 children (34.4%). With respect to the p roximal-distal distribution of the deletions, 90 children (77.6%) had delet ions exclusively at the 3' end of the gene, 21 deletions (18.1%) affected o nly the 5' end, and in five patients (4.3%) large-scale deletions were dete cted, which affected both regions. Analysis of the breakpoint distribution pattern in the dystrophin gene showed that, similarly to that observed in s everal Western European populations, intron 44 was involved most frequently (n = 35, 15.1%) as a starting breakpoint. In the Hungarian population intr ons 50 and 52 were the second (n = 30, 12.9%) and third (n = 29, 12.5%) mos t frequently observed hot spots at the 3' end; these seem to be characteris tic for the Hungarian patients. At the 5' end the breakpoint peak (n = 6, 2 .58%) was in intron two. As it was proposed by previous national studies, o ur findings also suggest that certain intronic sequences, characteristic fo r a population probably determine the development of a preferential breakpo int profile in this disease. (C) 1999 Elsevier Science B.V. All rights rese rved.