Exon skipping induced by nonsense/frameshift mutations in DMD gene results in Becker muscular dystrophy.
Hum Genet
; 139(2): 247-255, 2020 Feb.
Article
em En
| MEDLINE
| ID: mdl-31919629
ABSTRACT
Duchenne muscular dystrophy (DMD) is caused by a nonsense or frameshift mutation in the DMD gene, while its milder form, Becker muscular dystrophy (BMD) is caused by an in-frame deletion/duplication or a missense mutation. Interestingly, however, some patients with a nonsense mutation exhibit BMD phenotype, which is mostly attributed to the skipping of the exon containing the nonsense mutation, resulting in in-frame deletion. This study aims to find BMD cases with nonsense/frameshift mutations in DMD and to investigate the exon skipping rate of those nonsense/frameshift mutations. We searched for BMD cases with nonsense/frameshift mutations in DMD in the Japanese Registry of Muscular Dystrophy. For each DMD mutation identified, we constructed minigene plasmids containing one exon with/without a mutation and its flanking intronic sequence. We then introduced them into HeLa cells and measured the skipping rate of transcripts of the minigene by RT-qPCR. We found 363 cases with a nonsense/frameshift mutation in DMD gene from a total of 1497 dystrophinopathy cases in the registry. Among them, 14 had BMD phenotype. Exon skipping rates were well correlated with presence or absence of dystrophin, suggesting that 5% exon skipping rate is critical for the presence of dystrophin in the sarcolemma, leading to milder phenotypes. Accurate quantification of the skipping rate is important in understanding the exact functions of the nonsense/frameshift mutations in DMD and for interpreting the phenotypes of the BMD patients.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Éxons
/
Distrofina
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Mutação da Fase de Leitura
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Códon sem Sentido
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Distrofia Muscular de Duchenne
Tipo de estudo:
Etiology_studies
/
Incidence_studies
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Adolescent
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Adult
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Child
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article