rs587780488
Variant summary
Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PP2PP3_StrongPP5
The NM_001267550.2(TTN):c.40558G>C(p.Val13520Leu) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000133 in 1,427,914 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V13520I) has been classified as Likely benign.
Frequency
Consequence
NM_001267550.2 missense, splice_region
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_pathogenic. Variant got 6 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
---|---|---|---|---|---|---|---|
TTN | NM_001267550.2 | c.40558G>C | p.Val13520Leu | missense_variant, splice_region_variant | 219/363 | ENST00000589042.5 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|
TTN | ENST00000589042.5 | c.40558G>C | p.Val13520Leu | missense_variant, splice_region_variant | 219/363 | 5 | NM_001267550.2 | P1 | |
TTN-AS1 | ENST00000659121.1 | n.502+44556C>G | intron_variant, non_coding_transcript_variant |
Frequencies
GnomAD3 genomes ? Cov.: 32
GnomAD4 exome AF: 0.0000133 AC: 19AN: 1427914Hom.: 0 Cov.: 30 AF XY: 0.0000198 AC XY: 14AN XY: 707114
GnomAD4 genome ? Cov.: 32
ClinVar
Submissions by phenotype
not provided Pathogenic:2Uncertain:3
Uncertain significance, criteria provided, single submitter | clinical testing | Genetic Services Laboratory, University of Chicago | Feb 03, 2014 | - - |
Uncertain significance, criteria provided, single submitter | clinical testing | Athena Diagnostics | Mar 10, 2020 | - - |
Likely pathogenic, criteria provided, single submitter | clinical testing | GeneDx | Dec 24, 2015 | The c.35635G>C (V11879L, aka c.32854 G>C or V10952L) variant in the TTN gene has been published previouslyin one individual with dilated cardiomyopathy (DCM) (Herman et al., 2012). This variant has also been reported inassociation with autosomal recessive centronuclear myopathy (CNM) (Ceyhan-Birsoy et al., 2013; Brownstein et al.,2014). The c.32854 G>C variant has been identified at GeneDx in one family with autosomal recessive CNM whoalso harbor a TTN canonical splice site variant in trans. The c.35635G>C variant was not associated with anincreased risk of DCM in family members who only harbored this variant. This variant is located in the I-band regionof titin and a splicing assay demonstrated that the c.35635 G>C variant results in skipping of exon 168 leading toeither a truncated protein product or complete absence of protein from this allele due to nonsense mediated mRNAdecay (Ceyhan-Birsoy et al., 2013). Other splice site variants have been reported in the Human Gene MutationDatabase in association with autosomal recessive CNM and autosomal dominant DCM (Stenson et al., 2014).Furthermore, the NHLBI Exome Sequencing Project reports c.32854 G>C was not observed in approximately 5,900individuals of European and African American backgrounds, indicating it is not a common benign variant in thesepopulations. However, other truncating TTN variants have been reported in approximately 3% of control alleles(Herman et al., 2012). The contribution of the c.35635 G>C variant to the pathogenesis of autosomal dominant DCMis unclear. Therefore, this variant is likely pathogenic. - |
Uncertain significance, criteria provided, single submitter | clinical testing | AiLife Diagnostics, AiLife Diagnostics | Jan 26, 2022 | - - |
Likely pathogenic, criteria provided, single submitter | clinical testing | CeGaT Center for Human Genetics Tuebingen | Sep 01, 2023 | TTN: PM2, PM3, PP3, PS3:Supporting, PS4:Supporting - |
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Pathogenic:1
Pathogenic, criteria provided, single submitter | clinical testing | Invitae | Nov 03, 2023 | This sequence change replaces valine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 13520 of the TTN protein (p.Val13520Leu). RNA analysis indicates that this missense change induces altered splicing and likely results in a shortened protein product. This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with autosomal recessive centronuclear myopathy or limb-girdle muscular dystrophy and/or dilated cardiomyopathy (PMID: 22335739, 23975875, 30681174). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is also known as c.35635G>C or c.32854G>C. ClinVar contains an entry for this variant (Variation ID: 130666). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this missense change results in skipping of exon 219, but is expected to preserve the integrity of the reading-frame (PMID: 23975875). This variant is located in the I band of TTN (PMID: 25589632). Truncating variants in this region have been reported in individuals affected with autosomal recessive centronuclear myopathy (PMID: 23975875). Truncating variants in this region have also been identified in individuals affected with autosomal dominant dilated cardiomyopathy and/or cardio-related conditions (PMID: 27869827, 32964742). For these reasons, this variant has been classified as Pathogenic. - |
Dilated cardiomyopathy 1G Pathogenic:1
Likely pathogenic, no assertion criteria provided | clinical testing | Genomics England Pilot Project, Genomics England | - | - - |
Primary dilated cardiomyopathy Uncertain:1
Uncertain significance, 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. - |
Cardiomyopathy Other:1
not provided, no classification provided | phenotyping only | GenomeConnect, ClinGen | - | Variant classified as pathogenic on 12/26/2012 by GeneDx. GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. - |
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at