chr2-178615748-T-C
Position:
Variant summary
Our verdict is Likely benign. Variant got -4 ACMG points: 1P and 5B. PP2BP4_StrongBP6
The NM_001267550.2(TTN):āc.48353A>Gā(p.Asp16118Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000819 in 1,612,042 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Genomes: š 0.00015 ( 0 hom., cov: 32)
Exomes š: 0.000075 ( 0 hom. )
Consequence
TTN
NM_001267550.2 missense
NM_001267550.2 missense
Scores
3
4
10
Clinical Significance
Conservation
PhyloP100: 7.88
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]
Genome browser will be placed here
ACMG classification
Classification made for transcript
Verdict is Likely_benign. Variant got -4 ACMG points.
PP2
Missense variant in gene, where missense usually causes diseases (based on misZ statistic), TTN. . Gene score misZ -1.1021 (greater than the threshold 3.09). Trascript score misZ 6.9794 (greater than threshold 3.09). GenCC has associacion of gene with dilated cardiomyopathy, tibial muscular dystrophy, early-onset myopathy with fatal cardiomyopathy, autosomal recessive centronuclear myopathy, hypertrophic cardiomyopathy, hypertrophic cardiomyopathy 9, TTN-related myopathy, dilated cardiomyopathy 1G, arrhythmogenic right ventricular cardiomyopathy, myopathy, myofibrillar, 9, with early respiratory failure, familial isolated dilated cardiomyopathy, childhood-onset progressive contractures-limb-girdle weakness-muscle dystrophy syndrome, autosomal recessive limb-girdle muscular dystrophy type 2J.
BP4
Computational evidence support a benign effect (MetaRNN=0.015100092).
BP6
Variant 2-178615748-T-C is Benign according to our data. Variant chr2-178615748-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 179187.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=4, Uncertain_significance=4, Benign=4}. Variant chr2-178615748-T-C is described in Lovd as [Benign]. Variant chr2-178615748-T-C is described in Lovd as [Likely_benign].
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| TTN | NM_001267550.2 | c.48353A>G | p.Asp16118Gly | missense_variant | 258/363 | ENST00000589042.5 | NP_001254479.2 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| TTN | ENST00000589042.5 | c.48353A>G | p.Asp16118Gly | missense_variant | 258/363 | 5 | NM_001267550.2 | ENSP00000467141.1 |
Frequencies
GnomAD3 genomes 0.000158 AC: 24AN: 151892Hom.: 0 Cov.: 32
GnomAD3 genomes
AF:
AC:
24
AN:
151892
Hom.:
Cov.:
32
Gnomad AFR
AF:
Gnomad AMI
AF:
Gnomad AMR
AF:
Gnomad ASJ
AF:
Gnomad EAS
AF:
Gnomad SAS
AF:
Gnomad FIN
AF:
Gnomad MID
AF:
Gnomad NFE
AF:
Gnomad OTH
AF:
GnomAD3 exomes AF: 0.000218 AC: 54AN: 247994Hom.: 1 AF XY: 0.000178 AC XY: 24AN XY: 134530
GnomAD3 exomes
AF:
AC:
54
AN:
247994
Hom.:
AF XY:
AC XY:
24
AN XY:
134530
Gnomad AFR exome
AF:
Gnomad AMR exome
AF:
Gnomad ASJ exome
AF:
Gnomad EAS exome
AF:
Gnomad SAS exome
AF:
Gnomad FIN exome
AF:
Gnomad NFE exome
AF:
Gnomad OTH exome
AF:
GnomAD4 exome AF: 0.0000747 AC: 109AN: 1460032Hom.: 0 Cov.: 32 AF XY: 0.0000799 AC XY: 58AN XY: 726322
GnomAD4 exome
AF:
AC:
109
AN:
1460032
Hom.:
Cov.:
32
AF XY:
AC XY:
58
AN XY:
726322
Gnomad4 AFR exome
AF:
Gnomad4 AMR exome
AF:
Gnomad4 ASJ exome
AF:
Gnomad4 EAS exome
AF:
Gnomad4 SAS exome
AF:
Gnomad4 FIN exome
AF:
Gnomad4 NFE exome
AF:
Gnomad4 OTH exome
AF:
GnomAD4 genome 0.000151 AC: 23AN: 152010Hom.: 0 Cov.: 32 AF XY: 0.000202 AC XY: 15AN XY: 74274
GnomAD4 genome
AF:
AC:
23
AN:
152010
Hom.:
Cov.:
32
AF XY:
AC XY:
15
AN XY:
74274
Gnomad4 AFR
AF:
Gnomad4 AMR
AF:
Gnomad4 ASJ
AF:
Gnomad4 EAS
AF:
Gnomad4 SAS
AF:
Gnomad4 FIN
AF:
Gnomad4 NFE
AF:
Gnomad4 OTH
AF:
Alfa
AF:
Hom.:
Bravo
AF:
ExAC
AF:
AC:
24
Asia WGS
AF:
AC:
10
AN:
3478
ClinVar
Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:4Benign:12
Revision: criteria provided, conflicting classifications
LINK: link
Submissions by phenotype
not provided Uncertain:1Benign:4
| Uncertain significance, criteria provided, single submitter | clinical testing | Eurofins Ntd Llc (ga) | Oct 21, 2016 | - - |
| Likely benign, no assertion criteria provided | clinical testing | Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center | - | - - |
| Likely benign, criteria provided, single submitter | research | Biesecker Lab/Clinical Genomics Section, National Institutes of Health | Jun 24, 2013 | - - |
| Likely benign, no assertion criteria provided | clinical testing | Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+ | - | - - |
| Likely benign, criteria provided, single submitter | clinical testing | GeneDx | Dec 03, 2020 | This variant is associated with the following publications: (PMID: 23861362) - |
not specified Benign:3
| Benign, criteria provided, single submitter | clinical testing | Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine | Jun 05, 2018 | proposed classification - variant undergoing re-assessment, contact laboratory - |
| Benign, no assertion criteria provided | clinical testing | Clinical Genetics, Academic Medical Center | - | - - |
| Benign, criteria provided, single submitter | clinical testing | Women's Health and Genetics/Laboratory Corporation of America, LabCorp | Mar 07, 2022 | Variant summary: TTN c.40649A>G (p.Asp13550Gly) results in a non-conservative amino acid change located in the A-band of the encoded protein sequence. Three of four in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00022 in 247994 control chromosomes, predominantly at a frequency of 0.0026 within the East Asian subpopulation in the gnomAD database, including 1 homozygotes. The observed variant frequency within East Asian control individuals in the gnomAD database is approximately 7 fold of the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Dilated Cardiomyopathy phenotype (0.00039), strongly suggesting that the variant is a benign polymorphism found primarily in populations of East Asian origin. Seven clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Multiple laboratories reported the variant with conflicting assessments (Benign/likely benign n=5, VUS n=2). Based on the evidence outlined above, the variant was classified as benign. - |
Autosomal recessive limb-girdle muscular dystrophy type 2J Uncertain:1
| Uncertain significance, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Apr 27, 2017 | This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. - |
Dilated cardiomyopathy 1G Uncertain:1
| Uncertain significance, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Apr 27, 2017 | This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. - |
Early-onset myopathy with fatal cardiomyopathy Uncertain:1
| Uncertain significance, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Apr 27, 2017 | This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. - |
TTN-related disorder Benign:1
| Likely benign, no assertion criteria provided | clinical testing | PreventionGenetics, part of Exact Sciences | Aug 24, 2020 | This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). - |
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
| Likely benign, criteria provided, single submitter | clinical testing | Labcorp Genetics (formerly Invitae), Labcorp | Jan 21, 2024 | - - |
Tibial muscular dystrophy Benign:1
| Benign, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | May 24, 2017 | This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. - |
Myopathy, myofibrillar, 9, with early respiratory failure Benign:1
| Benign, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | May 24, 2017 | This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. - |
Cardiovascular phenotype Benign:1
| Likely benign, criteria provided, single submitter | clinical testing | Ambry Genetics | Jun 26, 2019 | In silico models in agreement (benign);Subpopulation frequency in support of benign classification - |
Computational scores
Source:
Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
BayesDel_addAF
Benign
T
BayesDel_noAF
Benign
CADD
Benign
DANN
Benign
Eigen
Uncertain
Eigen_PC
Pathogenic
FATHMM_MKL
Pathogenic
D
LIST_S2
Uncertain
D;D;D;.;D;D;D
M_CAP
Benign
D
MetaRNN
Benign
T;T;T;T;T;T;T
MetaSVM
Benign
T
MutationAssessor
Benign
.;.;.;N;.;.;N
PrimateAI
Uncertain
T
PROVEAN
Pathogenic
D;D;.;.;D;D;.
REVEL
Uncertain
Sift
Benign
T;T;.;.;T;T;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
MutPred
0.56
.;.;.;Gain of catalytic residue at L14478 (P = 0.1139);.;.;Gain of catalytic residue at L14478 (P = 0.1139);
MVP
MPC
0.53
ClinPred
T
GERP RS
Splicing
Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
Details are displayed if max score is > 0.2
Find out detailed SpliceAI scores and Pangolin per-transcript scores at