UK NHS diagnostic service sequence analysis of genes generally examines and reports on variations within a designated region 5' and 3' of each exon, typically 30 bp up and downstream. However, because of the degenerate nature of the splice sites, intronic variants outside the AG and GT dinucleotides of the acceptor and donor splice sites (ASS and DSS) are most often classified as being of unknown clinical significance, unless there is some functional evidence of their pathogenicity. It is now becoming clear that mutations deep within introns can also interfere with normal processing of pre-mRNA and result in pathogenic effects on the mature transcript. In diagnostic laboratories, these deep intronic variants most often fall outside of the regions analysed and so are rarely reported. With the likelihood that next generation sequencing will identify more of these unclassified variants, it will become important to perform additional studies to determine the pathogenicity of such sequence anomalies. Here, we analyse variants detected in either COL2A1 or COL11A1 in patients with Stickler syndrome. These have been analysed both in silico and functionally using either RNA isolated from the patient's cells or, more commonly, minigenes as splicing reporters. We show that deep intronic mutations are not a rare occurrence, including one variant that results in multiple transcripts, where both de novo donor and ASS are created by the mutation. Another variant produces transcripts that result in either haploinsufficiency or a dominant negative effect, potentially modifying the disease phenotype.
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http://dx.doi.org/10.1038/ejhg.2011.223 | DOI Listing |
Clin Genet
January 2025
Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India.
In 2021, the Indian Undiagnosed Diseases Program was initiated for patients without a definite diagnosis despite extensive evaluation in four participating sites. Between February 2021 and March 2023, a total of 88 patients were recruited and underwent deep phenotyping. A uniform methodology for data re-analysis was implemented as the first step prior to conducting additional genomic testing.
View Article and Find Full Text PDFPLoS Comput Biol
January 2025
Department of Computer Science, Colorado State University, Fort Collins, Colorado, United States of America.
Complex deep learning models trained on very large datasets have become key enabling tools for current research in natural language processing and computer vision. By providing pre-trained models that can be fine-tuned for specific applications, they enable researchers to create accurate models with minimal effort and computational resources. Large scale genomics deep learning models come in two flavors: the first are large language models of DNA sequences trained in a self-supervised fashion, similar to the corresponding natural language models; the second are supervised learning models that leverage large scale genomics datasets from ENCODE and other sources.
View Article and Find Full Text PDFNat Commun
January 2025
Division of Genome Analysis Platform Development, National Cancer Center Research Institute, Tokyo, Japan.
Genomic variants causing abnormal splicing play important roles in genetic disorders and cancer development. Among them, variants that cause the formation of novel splice-sites (splice-site creating variants, SSCVs) are particularly difficult to identify and often overlooked in genomic studies. Additionally, these SSCVs are frequently considered promising candidates for treatment with splice-switching antisense oligonucleotides (ASOs).
View Article and Find Full Text PDFExp Eye Res
January 2025
Genetic Diagnosis Unit, Institute for Rare Diseases Research (IIER), Institute of Health Carlos III (ISCIII), Madrid, Spain; CIBER of Rare Diseases (CIBERER), U758. Institute of Health Carlos III (ISCIII), Madrid, Spain.
Constitutional variants in the RB1 gene predispose individuals to the development of Retinoblastoma (RB) and the occurrence of second tumors in adulthood. Detection of causal RB1 gene variants is essential to establish the genetic diagnosis and to performing familial studies and counseling. In our cohort of 579 Spanish RB patients, 15% of cases suspected to have a genetic origin remained negative after traditional Sanger sequencing and Multiplex Ligation-dependent Probe Amplification (MLPA) of RB1 gene, likely due to the possibility of mosaicism or non-coding variants.
View Article and Find Full Text PDFGenes (Basel)
November 2024
Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland.
Stargardt disease (STGD1) is an autosomal recessive disorder caused by pathogenic variants in that affects the retina and is characterised by progressive central vision loss. The onset of disease manifestations varies from childhood to early adulthood. Whole exome (WES), whole gene, and whole genome sequencing (WGS) were performed for a patient with STGD1.
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