scholarly journals A Severe Case of Spondylometaphyseal Dysplasia Algerian Type with Two Mutations in COL2A1

2021 ◽  
Author(s):  
Francisco Cammarata-Scalisi ◽  
Uta Matysiak ◽  
Colin E. Willoughby ◽  
Gunda Ruzaike ◽  
Antonio Cárdenas Tadich ◽  
...  
Keyword(s):  
Autosomal Dominant ◽  
Severe Case ◽  
Splice Acceptor Site ◽  
Acceptor Site ◽  
Sequence Variant ◽  
Col2a1 Gene ◽  
Variant Of Unknown Significance ◽  
Spondylometaphyseal Dysplasia ◽  
Unknown Significance ◽  
Lumbar Hyperlordosis

AbstractSpondylometaphyseal dysplasia Algerian type (MIM no.: 184253) is an uncommon autosomal dominant skeletal dysplasia caused by heterozygous mutations in the COL2A1 gene (MIM no.: 120140). In this case based review, we reported a 5-year-old boy with short stature, severe dorsolumbar scoliosis, lumbar hyperlordosis, short trunk, and severe genu valgum. Radiological examination showed platyspondyly, irregular metaphyseal radiolucencies intermingled with radiodensities, and corner fractures. The patient has a c.3275G > A; p.Gly1092Asp mutation in exon 47 of the COL2A1 gene and a variant of unknown significance in c.1366–13C > A in intron 21. This latter sequence variant could partially or completely disrupt the natural splice acceptor site of intron 21/exon 22 in the COL2A1 gene leading to a potential modification of the phenotypic severity.

scholarly journals Contribution of Noncanonical Splice Variants to TTN Truncating Variants Cardiomyopathy

2021 ◽  
Author(s):  
Parth N. Patel ◽  
Kaoru Ito ◽  
Jon A.L. Willcox ◽  
Alireza Haghighi ◽  
Min Young Jang ◽  
...  
Keyword(s):  
Splice Variants ◽  
Donor Site ◽  
Idiopathic Dilated Cardiomyopathy ◽  
Splice Acceptor Site ◽  
Splice Donor Site ◽  
Acceptor Site ◽  
Variants Of Unknown Significance ◽  
Clinical Variant ◽  
Unknown Significance

Background: Heterozygous TTN truncating variants cause 10% to 20% of idiopathic dilated cardiomyopathy (DCM). Although variants which disrupt canonical splice signals (ie, invariant dinucleotide of splice donor site, invariant dinucleotide of the splice acceptor site) at exon-intron junctions are readily recognized as TTN truncating variants, the effects of other nearby sequence variations on splicing and their contribution to disease is uncertain. Methods: Rare variants of unknown significance located in the splice regions of highly expressed TTN exons from 203 DCM cases, 3329 normal subjects, and clinical variant databases were identified. The effects of these variants on splicing were assessed using an in vitro splice assay. Results: Splice-altering variants of unknown significance were enriched in DCM cases over controls and present in 2% of DCM patients ( P =0.002). Application of this method to clinical variant databases demonstrated 20% of similar variants of unknown significance in TTN splice regions affect splicing. Noncanonical splice-altering variants were most frequently located at position +5 of the donor site ( P =4.4×10 7 ) and position -3 of the acceptor site ( P =0.002). SpliceAI, an emerging in silico prediction tool, had a high positive predictive value (86%–95%) but poor sensitivity (15%–50%) for the detection of splice-altering variants. Alternate exons spliced out of most TTN transcripts frequently lacked the consensus base at +5 donor and −3 acceptor positions. Conclusions: Noncanonical splice-altering variants in TTN explain 1-2% of DCM and offer a 10-20% increase in the diagnostic power of TTN sequencing in this disease. These data suggest rules that may improve efforts to detect splice-altering variants in other genes and may explain the low percent splicing observed for many alternate TTN exons.

scholarly journals Functional testing of a human PBX3 variant in zebrafish reveals a potential modifier role in congenital heart defects

2018 ◽  
Author(s):  
Gist H. Farr ◽  
Kimia Imani ◽  
Darren Pouv ◽  
Lisa Maves
Keyword(s):  
Genome Editing ◽  
Congenital Heart Defects ◽  
Heart Development ◽  
Congenital Heart ◽  
Heart Defects ◽  
Sequence Variant ◽  
Functional Testing ◽  
Complex Genetics ◽  
Variant Of Unknown Significance ◽  
Unknown Significance

AbstractWhole-genome and whole-exome sequencing efforts are increasingly identifying candidate genetic variants associated with human disease. However, predicting and testing the pathogenicity of a genetic variant remains challenging. Genome editing allows for the rigorous functional testing of human genetic variants in animal models. Congenital heart defects (CHDs) are a prominent example of a human disorder with complex genetics. An inherited sequence variant in the human PBX3 gene (PBX3 p.A136V) has previously been shown to be enriched in a CHD patient cohort, indicating that the PBX3 p.A136V variant could be a modifier allele for CHDs. PBX genes encode TALE (Three Amino acid Loop Extension)-class homeodomain-containing DNA-binding proteins with diverse roles in development and disease and are required for heart development in mouse and zebrafish. Here we use CRISPR-Cas9 genome editing to directly test whether this PBX gene variant acts as a genetic modifier in zebrafish heart development. We used a single-stranded oligodeoxynucleotide to precisely introduce the human PBX3 p.A136V variant in the homologous zebrafish pbx4 gene (pbx4 p.A131V). We find that zebrafish that are homozygous for pbx4 p.A131V are viable as adults. However, we show that the pbx4 p.A131V variant enhances the embryonic cardiac morphogenesis phenotype caused by loss of the known cardiac specification factor, Hand2. Our study is the first example of using precision genome editing in zebrafish to demonstrate a function for a human disease-associated single nucleotide variant of unknown significance. Our work underscores the importance of testing the roles of inherited variants, not just de novo variants, as genetic modifiers of CHDs. Our study provides a novel approach toward advancing our understanding of the complex genetics of CHDs.Summary statementOur study provides a novel example of using genome editing in zebrafish to demonstrate how a human DNA sequence variant of unknown significance may contribute to the complex genetics of congenital heart defects.

scholarly journals The Caveolin-3 G56S sequence variant of unknown significance: Muscle biopsy findings and functional cell biological analysis

2016 ◽  
Vol 11 (1-2) ◽  
pp. 1600007 ◽  
Author(s):  
Eva Brauers ◽  
Andreas Roos ◽  
Laxmikanth Kollipara ◽  
René P. Zahedi ◽  
Alf Beckmann ◽  
...  
Keyword(s):  
Muscle Biopsy ◽  
Sequence Variant ◽  
Biological Analysis ◽  
Variant Of Unknown Significance ◽  
Unknown Significance

scholarly journals Splice-acceptor site mutation in p53 gene of hu888 zebrafish line

2014 ◽  
Vol 56 (1) ◽  
pp. 115-121 ◽  
Author(s):  
Alicja Piasecka ◽  
Paweł Brzuzan ◽  
Maciej Woźny ◽  
Sławomir Ciesielski ◽  
Dariusz Kaczmarczyk
Keyword(s):  
P53 Gene ◽  
Splice Acceptor Site ◽  
Acceptor Site ◽  
Splice Acceptor ◽  
Site Mutation ◽  
Splice Acceptor Site Mutation

scholarly journals Nova Regulates GABAA Receptor γ2 Alternative Splicing via a Distal Downstream UCAU-Rich Intronic Splicing Enhancer

2003 ◽  
Vol 23 (13) ◽  
pp. 4687-4700 ◽  
Author(s):  
B. Kate Dredge ◽  
Robert B. Darnell
Keyword(s):  
Alternative Splicing ◽  
Rna Binding ◽  
Splice Acceptor Site ◽  
Acceptor Site ◽  
Splicing Regulation ◽  
Globin Genes ◽  
Enhancer Element ◽  
Intronic Splicing Enhancer ◽  
Splicing Enhancer

ABSTRACT Nova is a neuron-specific RNA binding protein targeted in patients with the autoimmune disorder paraneoplastic opsoclonus-myoclonus ataxia, which is characterized by failure of inhibition of brainstem and spinal motor systems. Here, we have biochemically confirmed the observation that splicing regulation of the inhibitory GABAA receptor γ2 (GABAARγ2) subunit pre-mRNA exon E9 is disrupted in mice lacking Nova-1. To elucidate the mechanism by which Nova-1 regulates GABAARγ2 alternative splicing, we systematically screened minigenes derived from the GABAARγ2 and human β-globin genes for their ability to support Nova-dependent splicing in transient transfection assays. These studies demonstrate that Nova-1 acts directly on GABAARγ2 pre-mRNA to regulate E9 splicing and identify an intronic region that is necessary and sufficient for Nova-dependent enhancement of exon inclusion, which we term the NISE (Nova-dependent intronic splicing enhancer) element. The NISE element (located 80 nucleotides upstream of the splice acceptor site of the downstream exon E10) is composed of repeats of the sequence YCAY, consistent with previous studies of the mechanism by which Nova binds RNA. Mutation of these repeats abolishes binding of Nova-1 to the RNA in vitro and Nova-dependent splicing regulation in vivo. These data provide a molecular basis for understanding Nova regulation of GABAARγ2 alternative splicing and suggest that general dysregulation of Nova's splicing enhancer function may underlie the neurologic defects seen in Nova's absence.

scholarly journals A splice junction deletion deficient in the transport of RNA does not polyadenylate nuclear RNA.

1983 ◽  
Vol 3 (8) ◽  
pp. 1381-1388 ◽  
Author(s):  
L P Villarreal ◽  
R T White
Keyword(s):  
Simian Virus 40 ◽  
Splice Junction ◽  
Simian Virus ◽  
The Body ◽  
Splice Acceptor Site ◽  
Acceptor Site ◽  
Wild Type ◽  
Normal Position ◽  
Nuclear Rna ◽  
Late Region

A late region deletion mutant of simian virus 40 (dl5) was previously shown to be deficient in the transport of nuclear RNA. This is a splice junction deletion that has lost the 3' end of an RNA leader, an intervening sequence, and the 5' end of the splice acceptor site on the body of the mRNA. In this report, we analyzed the steady-state structure of the untransported nuclear RNA. The 5' ends of this RNA are heterogeneous but contain a prominent 5' end at the normal position (nucleotide 325) in addition to several other prominent 5' ends not seen in wild-type RNA. The 3' end of this RNA does not occur at the usual position (nucleotide 2674) of polyadenylation; instead, this RNA is non-polyadenylated, with the 3' end occurring either downstream or upstream of the normal position.

scholarly journals Procyclic acidic repetitive protein (PARP) genes located in an unusually small alpha-amanitin-resistant transcription unit: PARP promoter activity assayed by transient DNA transfection of Trypanosoma brucei.

1990 ◽  
Vol 10 (7) ◽  
pp. 3492-3504 ◽  
Author(s):  
G Rudenko ◽  
S Le Blancq ◽  
J Smith ◽  
M G Lee ◽  
A Rattray ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Transcription Unit ◽  
Splice Acceptor Site ◽  
Acceptor Site ◽  
Nucleotide Position ◽  
Splice Acceptor ◽  
Transcription Analysis ◽  
Alpha Amanitin ◽  
Single Promoter ◽  
Repetitive Protein

At least one of the procyclic acidic repetitive protein (PARP or procyclin) loci of Trypanosoma brucei is a small (5- to 6-kilobase) polycistronic transcription unit which is transcribed in an alpha-amanitin-resistant manner. Its single promoter, as mapped by run-on transcription analysis and UV inactivation of transcription, is located immediately upstream of the first alpha-PARP gene. Transcription termination occurs in a region approximately 3 kilobases downstream of the beta-PARP gene. The location of the promoter was confirmed by its ability to direct transcription of the bacterial chloramphenicol acetyltransferase gene in insect-form (procyclic) T. brucei. The putative PARP promoter is located in the region between the 3' splice acceptor site (nucleotide position 0) and nucleotide position -196 upstream of the alpha-PARP genes. Regulatory regions influencing the levels of PARP expression may be located further upstream. We conclude that a single promoter, which is located very close to the 3' splice acceptor site of the alpha-PARP genes, directs the transcription of a small, polycistronic, and alpha-amanitin-resistant transcription unit.

Alpha 2-chimerin, an SH2-containing GTPase-activating protein for the ras-related protein p21rac derived by alternate splicing of the human n-chimerin gene, is selectively expressed in brain regions and testes

1993 ◽  
Vol 13 (8) ◽  
pp. 4986-4998
Author(s):  
C Hall ◽  
W C Sin ◽  
M Teo ◽  
G J Michael ◽  
P Smith ◽  
...  
Keyword(s):  
Rat Brain ◽  
Brain Regions ◽  
Sh2 Domain ◽  
Trophic Factors ◽  
Splice Acceptor Site ◽  
Acceptor Site ◽  
Related Protein ◽  
Gtpase Activating Protein ◽  
Alternate Splicing ◽  
Pachytene Spermatocytes

n-Chimerin (alpha 1-chimerin) is a brain GTPase-activating protein (GAP) for the ras-related p21rac. We now report the occurrence of another form of chimerin, termed alpha 2-chimerin. This is the product of an alternately spliced transcript of the human n-chimerin gene encoding an N-terminal SH2 (src homology 2) domain in addition to the phorbol ester receptor and GAP domains. alpha 1- and alpha 2-chimerin mRNAs were expressed differently. In the rat brain, only alpha 1-chimerin mRNA was expressed in cerebellar Purkinje cells, although both alpha 1- and alpha 2-chimerin mRNAs occurred in neurons in the cerebral cortex, hippocampus, and thalamus. Only alpha 2-chimerin RNA was expressed in rat testes, in early pachytene spermatocytes. A 45-kDa SH2-containing chimerin corresponding to the alpha 2 form was purified from rat brain. As with Escherichia coli 45-kDa recombinant alpha 2-chimerin, purified brain alpha 2-chimerin exhibited racGAP activity which was stimulated by phosphatidylserine. The recombinant SH2 domain bound several 32P-labelled phosphoproteins of PC12 cells, whose phosphorylation increased in response to trophic factors, including nerve growth factor. To examine the relationships of alpha 1- and alpha 2-chimerin transcripts, human genomic DNA clones were characterized. In alpha 2-chimerin mRNA, a 3' splice acceptor site within exon 1 of alpha 1-chimerin mRNA was used, replacing its 5' untranslated region and N-terminal coding sequence. The single human n-chimerin gene was mapped to chromosome 2q31-q32.1, colocalizing with the CRE-BP1 transcription factor gene (2q32). It contained several splice junctions conserved with the sequence-related protein kinase C and bcr genes. alpha 2-Chimerin is only the second SH2-containing GAP and the first example of an SH2 domain generated by alternate splicing.

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