rs1477669354

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_001267550.2(TTN):​c.107284C>T​(p.Arg35762*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,613,768 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. R35762R) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

TTN
NM_001267550.2 stop_gained

Scores

4
3
7

Clinical Significance

Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 2.33

Publications

2 publications found
Variant links:
Genes affected
TTN (HGNC:12403): (titin) This gene encodes a large abundant protein of striated muscle. The product of this gene is divided into two regions, a N-terminal I-band and a C-terminal A-band. The I-band, which is the elastic part of the molecule, contains two regions of tandem immunoglobulin domains on either side of a PEVK region that is rich in proline, glutamate, valine and lysine. The A-band, which is thought to act as a protein-ruler, contains a mixture of immunoglobulin and fibronectin repeats, and possesses kinase activity. An N-terminal Z-disc region and a C-terminal M-line region bind to the Z-line and M-line of the sarcomere, respectively, so that a single titin molecule spans half the length of a sarcomere. Titin also contains binding sites for muscle associated proteins so it serves as an adhesion template for the assembly of contractile machinery in muscle cells. It has also been identified as a structural protein for chromosomes. Alternative splicing of this gene results in multiple transcript variants. Considerable variability exists in the I-band, the M-line and the Z-disc regions of titin. Variability in the I-band region contributes to the differences in elasticity of different titin isoforms and, therefore, to the differences in elasticity of different muscle types. Mutations in this gene are associated with familial hypertrophic cardiomyopathy 9, and autoantibodies to titin are produced in patients with the autoimmune disease scleroderma. [provided by RefSeq, Feb 2012]
TTN-AS1 (HGNC:44124): (TTN antisense RNA 1) This gene encodes a non-coding RNA transcribed from the opposite strand to the titin gene. [provided by RefSeq, Aug 2016]

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP5
Variant 2-178528367-G-A is Pathogenic according to our data. Variant chr2-178528367-G-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 640886.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.107284C>T p.Arg35762* stop_gained Exon 361 of 363 ENST00000589042.5 NP_001254479.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.107284C>T p.Arg35762* stop_gained Exon 361 of 363 5 NM_001267550.2 ENSP00000467141.1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152146
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000274
AC:
4
AN:
1461622
Hom.:
0
Cov.:
31
AF XY:
0.00000413
AC XY:
3
AN XY:
727090
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26126
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39694
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53394
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1111816
Other (OTH)
AF:
0.00
AC:
0
AN:
60372
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152146
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74332
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41436
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5206
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4816
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10592
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.550
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Pathogenic:1
Jul 12, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Arg35762*) in the TTN gene. While this is not anticipated to result in nonsense mediated decay, it is expected to create a truncated TTN protein. This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with clinical features of TTN-related cardiomyopathies (PMID: 34540771, 36264615). ClinVar contains an entry for this variant (Variation ID: 640886). This variant is located in the M band of TTN (PMID: 25589632). Truncating variants in this region have been previously reported in individuals affected with autosomal recessive myopathy and muscular dystrophy (PMID: 18948003, 23975875, 24395473). 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, Invitae internal data). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic.

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1838244:Tibial muscular dystrophy;C1858763:Dilated cardiomyopathy 1G;C1861065:Hypertrophic cardiomyopathy 9;C1863599:Myopathy, myofibrillar, 9, with early respiratory failure;C2673677:Early-onset myopathy with fatal cardiomyopathy Pathogenic:1
Juno Genomics, Hangzhou Juno Genomics, Inc
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Absent from controls (or at extremely low frequency if recessive) in Genome Aggregation Database, Exome Sequencing Project, 1000 Genomes Project, or Exome Aggregation Consortium.;Null variant in a gene where loss of function (LOF) is a known mechanism of disease.

not provided Pathogenic:1
Jan 07, 2025
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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); Located in the M-band, a region of TTN for which truncating variants are significantly associated with autosomal recessive skeletal myopathies and also with autosomal dominant cardiomyopathy (PMID: 17444505, 32778822, 36637017); This variant is associated with the following publications: (PMID: 34540771, 38438525, 36264615, 17444505, 32778822, 36637017)

Left ventricular noncompaction cardiomyopathy Pathogenic:1
Klaassen Lab, Charite University Medicine Berlin
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.52
D
BayesDel_noAF
Pathogenic
0.51
CADD
Pathogenic
70
DANN
Benign
0.95
DEOGEN2
Benign
0.0
.;.;.;.;.;.;.
Eigen
Uncertain
0.65
Eigen_PC
Uncertain
0.47
FATHMM_MKL
Uncertain
0.79
D
LIST_S2
Benign
0.0
.;.;.;.;.;.;.
MetaRNN
Benign
0.0
.;.;.;.;.;.;.
MutationAssessor
Benign
0.0
.;.;.;.;.;.;.
PhyloP100
2.3
PROVEAN
Benign
0.0
.;.;.;.;.;.;.
REVEL
Benign
0.0
Sift
Pathogenic
0.0
.;.;.;.;.;.;.
Sift4G
Pathogenic
0.0
.;.;.;.;.;.;.
Vest4
0.67
GERP RS
4.4
Mutation Taster
=8/192
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs1477669354; hg19: chr2-179393094; COSMIC: COSV60043419; COSMIC: COSV60043419; API