2-178573350-C-T
Position:
Variant summary
Our verdict is Benign. Variant got -8 ACMG points: 1P and 9B. PP2BP4_StrongBP6BS1
The NM_001267550.2(TTN):c.72782G>A(p.Arg24261Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000326 in 1,535,896 control chromosomes in the GnomAD database, including 1 homozygotes. 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: 𝑓 0.0013 ( 1 hom., cov: 32)
Exomes 𝑓: 0.00022 ( 0 hom. )
Consequence
TTN
NM_001267550.2 missense
NM_001267550.2 missense
Scores
3
6
8
Clinical Significance
Conservation
PhyloP100: 7.86
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 Benign. Variant got -8 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=0.008477598).
BP6
Variant 2-178573350-C-T is Benign according to our data. Variant chr2-178573350-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 47317.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=6, Benign=6, Uncertain_significance=3}. Variant chr2-178573350-C-T is described in Lovd as [Benign]. Variant chr2-178573350-C-T is described in Lovd as [Likely_benign].
BS1
Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00132 (201/152104) while in subpopulation AFR AF= 0.00443 (184/41516). AF 95% confidence interval is 0.00391. There are 1 homozygotes in gnomad4. There are 97 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| TTN | NM_001267550.2 | c.72782G>A | p.Arg24261Gln | missense_variant | 326/363 | ENST00000589042.5 | NP_001254479.2 | |
| TTN-AS1 | NR_038272.1 | n.2044-9222C>T | intron_variant, non_coding_transcript_variant |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| TTN | ENST00000589042.5 | c.72782G>A | p.Arg24261Gln | missense_variant | 326/363 | 5 | NM_001267550.2 | ENSP00000467141 | P1 | |
| TTN-AS1 | ENST00000659121.1 | n.417-24246C>T | intron_variant, non_coding_transcript_variant |
Frequencies
GnomAD3 genomes 0.00132 AC: 200AN: 151986Hom.: 1 Cov.: 32
GnomAD3 genomes
AF:
AC:
200
AN:
151986
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: 0.000574 AC: 108AN: 188210Hom.: 1 AF XY: 0.000543 AC XY: 54AN XY: 99506
GnomAD3 exomes
AF:
AC:
108
AN:
188210
Hom.:
AF XY:
AC XY:
54
AN XY:
99506
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: 0.000216 AC: 299AN: 1383792Hom.: 0 Cov.: 38 AF XY: 0.000193 AC XY: 131AN XY: 679456
GnomAD4 exome
AF:
AC:
299
AN:
1383792
Hom.:
Cov.:
38
AF XY:
AC XY:
131
AN XY:
679456
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 0.00132 AC: 201AN: 152104Hom.: 1 Cov.: 32 AF XY: 0.00130 AC XY: 97AN XY: 74336
GnomAD4 genome
AF:
AC:
201
AN:
152104
Hom.:
Cov.:
32
AF XY:
AC XY:
97
AN XY:
74336
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:
TwinsUK
AF:
AC:
2
ALSPAC
AF:
AC:
0
ESP6500AA
AF:
AC:
14
ESP6500EA
AF:
AC:
0
ExAC
AF:
AC:
67
Asia WGS
AF:
AC:
1
AN:
3476
ClinVar
Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:3Benign:15
Revision: criteria provided, conflicting classifications
LINK: link
Submissions by phenotype
not provided Benign:6
| Likely benign, criteria provided, single submitter | research | Biesecker Lab/Clinical Genomics Section, National Institutes of Health | Jun 24, 2013 | - - |
| Likely benign, criteria provided, single submitter | clinical testing | CeGaT Center for Human Genetics Tuebingen | Apr 01, 2024 | TTN: BS2 - |
| 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 | clinical testing | ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories | Sep 20, 2022 | - - |
| Likely benign, criteria provided, single submitter | clinical testing | GeneDx | May 19, 2021 | - - |
| Likely benign, no assertion criteria provided | clinical testing | Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen | - | - - |
not specified Benign:4
| Benign, criteria provided, single submitter | clinical testing | Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine | Jul 29, 2015 | p.Arg21693Gln in exon 275 of TTN: This variant is not expected to have clinical significance because it has been identified in 0.5% (44/9628) of African chromos omes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org/; dbSNP rs142874389). - |
| 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 | Aug 24, 2020 | Variant summary: TTN c.65078G>A (p.Arg21693Gln) results in a conservative amino acid change located in the A-band region of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00057 in 188210 control chromosomes, predominantly at a frequency of 0.0051 within the African or African-American subpopulation in the gnomAD database, including 1 homozygote. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 13-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 African or African-American origin. To our knowledge, no occurrence of c.65078G>A in individuals affected with Dilated Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. Five clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation, and all of them classified the variant as benign (3x) or likely benign (2x). Based on the evidence outlined above, the variant was classified as benign. - |
| Likely benign, criteria provided, single submitter | clinical testing | Eurofins Ntd Llc (ga) | Sep 30, 2016 | - - |
Autosomal recessive limb-girdle muscular dystrophy type 2J Uncertain:1
| Uncertain significance, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Jan 12, 2018 | This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. - |
Dilated cardiomyopathy 1G Uncertain:1
| Uncertain significance, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Jan 12, 2018 | This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. - |
Early-onset myopathy with fatal cardiomyopathy Uncertain:1
| Uncertain significance, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Jan 12, 2018 | This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. - |
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
| Benign, criteria provided, single submitter | clinical testing | Labcorp Genetics (formerly Invitae), Labcorp | Feb 01, 2024 | - - |
Cardiomyopathy Benign:1
| Benign, criteria provided, single submitter | clinical testing | CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario | Sep 21, 2021 | - - |
Myopathy, myofibrillar, 9, with early respiratory failure Benign:1
| Benign, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Jan 12, 2018 | This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. - |
Tibial muscular dystrophy Benign:1
| Benign, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Jan 12, 2018 | This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. - |
Cardiovascular phenotype Benign:1
| Likely benign, criteria provided, single submitter | clinical testing | Ambry Genetics | Mar 19, 2019 | This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. - |
Computational scores
Source:
Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
BayesDel_addAF
Benign
T
BayesDel_noAF
Benign
CADD
Uncertain
DANN
Benign
Eigen
Pathogenic
Eigen_PC
Pathogenic
FATHMM_MKL
Uncertain
D
LIST_S2
Uncertain
D;D;D;.;D;D;D
M_CAP
Benign
T
MetaRNN
Benign
T;T;T;T;T;T;T
MetaSVM
Benign
T
MutationAssessor
Pathogenic
.;.;.;M;.;.;M
MutationTaster
Benign
D;D;D;D;D;D
PrimateAI
Uncertain
T
PROVEAN
Uncertain
D;D;.;.;D;D;.
REVEL
Uncertain
Sift
Uncertain
D;D;.;.;D;D;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
MVP
MPC
0.38
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