Deep-intronic ABCA4 variants explain missing heritability in Stargardt disease and allow correction of splice defects by antisense oligonucleotides.
Genet Med
; 21(8): 1751-1760, 2019 08.
Article
em En
| MEDLINE
| ID: mdl-30643219
ABSTRACT
PURPOSE:
Using exome sequencing, the underlying variants in many persons with autosomal recessive diseases remain undetected. We explored autosomal recessive Stargardt disease (STGD1) as a model to identify the missing heritability.METHODS:
Sequencing of ABCA4 was performed in 8 STGD1 cases with one variant and p.Asn1868Ile in trans, 25 cases with one variant, and 3 cases with no ABCA4 variant. The effect of intronic variants was analyzed using in vitro splice assays in HEK293T cells and patient-derived fibroblasts. Antisense oligonucleotides were used to correct splice defects.RESULTS:
In 24 of the probands (67%), one known and five novel deep-intronic variants were found. The five novel variants resulted in messenger RNA pseudoexon inclusions, due to strengthening of cryptic splice sites or by disrupting a splicing silencer motif. Variant c.769-784C>T showed partial insertion of a pseudoexon and was found in cis with c.5603A>T (p.Asn1868Ile), so its causal role could not be fully established. Variant c.4253+43G>A resulted in partial skipping of exon 28. Remarkably, antisense oligonucleotides targeting the aberrant splice processes resulted in (partial) correction of all splicing defects.CONCLUSION:
Our data demonstrate the importance of assessing noncoding variants in genetic diseases, and show the great potential of splice modulation therapy for deep-intronic variants.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oligonucleotídeos Antissenso
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Transportadores de Cassetes de Ligação de ATP
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Isoformas de Proteínas
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Doença de Stargardt
Limite:
Adolescent
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Adult
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Aged
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Child
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Humans
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Middle aged
Idioma:
En
Revista:
Genet Med
Assunto da revista:
GENETICA MEDICA
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Holanda