rs770767998
Variant summary
Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1PM2PP5
The NM_001267550.2(TTN):c.44284C>T(p.Arg14762Ter) variant causes a stop gained, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,460,556 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. R14762R) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.
Frequency
Consequence
NM_001267550.2 stop_gained, splice_region
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 11 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
---|---|---|---|---|---|---|---|
TTN | NM_001267550.2 | c.44284C>T | p.Arg14762Ter | stop_gained, splice_region_variant | 240/363 | ENST00000589042.5 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|
TTN | ENST00000589042.5 | c.44284C>T | p.Arg14762Ter | stop_gained, splice_region_variant | 240/363 | 5 | NM_001267550.2 | P1 | |
TTN-AS1 | ENST00000659121.1 | n.502+31760G>A | intron_variant, non_coding_transcript_variant |
Frequencies
GnomAD3 genomes ? Cov.: 33
GnomAD4 exome AF: 0.00000137 AC: 2AN: 1460556Hom.: 0 Cov.: 30 AF XY: 0.00000275 AC XY: 2AN XY: 726600
GnomAD4 genome ? Cov.: 33
ClinVar
Submissions by phenotype
Primary dilated cardiomyopathy Pathogenic:2
Likely pathogenic, criteria provided, single submitter | research | Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust | Oct 08, 2014 | This TTN truncating variant (TTNtv) was identified in one individual in this cohort and is located in an exon that is highly expressed in the heart. In the seven cohorts assessed, TTNtv were found in 14% of ambulant DCM, 22% end-stage or familial DCM, and 2% controls. Heterozygous nonsense, frameshift and canonical splice-disrupting variants found in constitutive and other highly utilised exons are highly likely to be pathogenic when identified in individuals with phenotypically confirmed DCM. TTNtv found incidentally in healthy individuals (excluding familial assessment of DCM relatives) are thought to have low penetrance, particularly when identified in exons that are not constitutively expressed in the heart. - |
Pathogenic, criteria provided, single submitter | clinical testing | Molecular Genetics, Royal Melbourne Hospital | Jul 07, 2023 | This sequence change in TTN is a nonsense variant predicted to cause a premature stop codon, p.(Arg14762*), in constitutively expressed exon 240 (percentage splice in, PSI, 100%) in the distal I-band. High PSI truncating variants in TTN have a significant association with dilated cardiomyopathy (PMID: 31216868). This variant is absent from the population database gnomAD v2.1 and v3.1. This variant has been reported in at least three probands with cardiomyopathy (PMID: 29961767, 33874732; ClinVar: SCV000189773.1). Based on the classification scheme RMH Modified ACMG/AMP Guidelines v1.6.1, this variant is classified as PATHOGENIC. Following criteria are met: PVS1, PM2_Supporting, PS4_Supporting - |
not provided Pathogenic:1
Pathogenic, criteria provided, single submitter | clinical testing | GeneDx | Aug 09, 2022 | Located in a region of TTN within the I-band in which the majority of loss of function variants are significantly associated with autosomal dominant titinopathies (Deo et al., 2016; Schafer et al., 2017); Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 29961767, 25589632, 33874732) - |
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Uncertain significance, criteria provided, single submitter | clinical testing | Invitae | Oct 25, 2022 | In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. This variant is located in the I band of TTN (PMID: 25589632). Truncating variants in this region have been shown to be highly prevalent in the general population and unaffected individuals (PMID: 26701604, 22335739). However, truncating variants in this region have also been reported in individuals affected with autosomal recessive centronuclear myopathy (PMID: 23975875). ClinVar contains an entry for this variant (Variation ID: 223369). This premature translational stop signal has been observed in individual(s) with dilated cardiomyopathy (PMID: 29961767, 33874732). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Arg14762*) in the TTN gene. While this is not anticipated to result in nonsense mediated decay, it is expected to create a truncated TTN protein. - |
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at