Abstract
Background: Inherited retinal diseases (IRDs) are clinically complex and genetically heterogeneous visual impairment disorders with varying penetrance and severity. Disease-causing variants in at least 289 nuclear and mitochondrial genes have been implicated in their pathogenesis. Methods: Whole exome sequencing results were analyzed using established pipelines and the results were further confirmed by Sanger sequencing and minigene splicing assay. Results: Exome sequencing in a 51-year-old Ashkenazi Jewish patient with non-syndromic retinitis pigmentosa (RP) identified compound heterozygous variants in the CLRN1 gene: a known pathogenic missense [p.(N48K)] and a novel deep intronic variant c.254-643G>T. A minigene splicing assay that was performed aiming to study the effect of the c.254-643G>T variant on CLRN1 pre-mRNA splicing revealed the inclusion of a pseudo-exon that was also reported to be included in the transcript due to an adjacent variant, c.254-649T>G. However, unlike the reported c.254-649T>G variant, c.254-643G>T showed aberrant splicing in a leaky manner, implying that the identified variant is not totally penetrant. Conclusion: We report on a novel deep intronic variant in CLRN1 causing non-syndromic RP. The non-syndromic phenotype observed in this index case may be attributed to the leaky nature of this variant, which is causing some normal transcripts to be produced.
Original language | English |
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Article number | 1363 |
Journal | Genes |
Volume | 15 |
Issue number | 11 |
DOIs | |
State | Published - Nov 2024 |
Bibliographical note
Publisher Copyright:© 2024 by the authors.
Keywords
- CLRN1
- deep intronic
- inherited retinal diseases
- pseudo-exon
- retinitis pigmentosa
- splicing