Protein- and mRNA-based phenotype-genotype correlations in DMD/BMD with point mutations and molecular basis for BMD with nonsense and frameshift mutations in the DMD gene.
Straightforward detectable Duchenne muscular dystrophy (DMD) gene rearrangements, such as deletions or duplications involving an entire exon or more, are involved in about 70% of dystrophinopathies. In the remaining 30% a variety of point mutations or "small" mutations are suspected. Due to their diversity and to the large size and complexity of the DMD gene, these point mutations are difficult to detect. To overcome this diagnostic issue, we developed and optimized a routine muscle biopsy-based diagnostic strategy. The mutation detection rate is almost as high as 100% and mutations were identified in all patients for whom the diagnosis of DMD and Becker muscular dystrophy (BMD) was clinically suspected and further supported by the detection on Western blot of quantitative and/or qualitative dystrophin protein abnormalities. Here we report a total of 124 small mutations including 11 nonsense and frameshift mutations detected in BMD patients. In addition to a comprehensive assessment of muscular phenotypes that takes into account consequences of mutations on the expression of the dystrophin mRNA and protein, we provide and discuss genomic, mRNA, and protein data that pinpoint molecular mechanisms underlying BMD phenotypes associated with nonsense and frameshift mutations.
Deburgrave
Nathalie
N
Institut Cochin, INSERM Unité 567, CNR UMR 1408, Université René Descartes Paris 5 UM3, Paris, France.
Daoud
Fatma
F
Llense
Stéphane
S
Barbot
Jean Claude
JC
Récan
Dominique
D
Peccate
Cécile
C
Burghes
Arthur H M
AH
Béroud
Christophe
C
Garcia
Luis
L
Kaplan
Jean-Claude
JC
Chelly
Jamel
J
Leturcq
France
F
D000293:Adolescent; D000328:Adult; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D018389:Codon, Nonsense; D004252:DNA Mutational Analysis / Q000379:methods; D018076:DNA, Complementary / Q000737:chemistry; D016189:Dystrophin / Q000235:genetics*; D005260:Female; D016368:Frameshift Mutation; D005838:Genotype; D006801:Humans; D008297:Male; D020388:Muscular Dystrophy, Duchenne / Q000175:diagnosis* / Q000235:genetics; D009154:Mutation; D010641:Phenotype; D017354:Point Mutation; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism
D018389:Codon, Nonsense; C484258:DMD protein, human; D018076:DNA, Complementary; D016189:Dystrophin; D012333:RNA, Messenger