rs188185141

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 1P and 5B. PP2BP4_StrongBP6

The NM_001267550.2(TTN):ā€‹c.57442A>Gā€‹(p.Met19148Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000666 in 1,613,262 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: š‘“ 0.00039 ( 0 hom., cov: 32)
Exomes š‘“: 0.00069 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

3
14

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:11B:12

Conservation

PhyloP100: 1.89
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 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=0.029392332).
BP6
Variant 2-178597640-T-C is Benign according to our data. Variant chr2-178597640-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 191935.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=11, Benign=2, Likely_benign=4}. Variant chr2-178597640-T-C is described in Lovd as [Likely_benign]. Variant chr2-178597640-T-C is described in Lovd as [Benign].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
TTNNM_001267550.2 linkuse as main transcriptc.57442A>G p.Met19148Val missense_variant 294/363 ENST00000589042.5
TTN-AS1NR_038272.1 linkuse as main transcriptn.3409T>C non_coding_transcript_exon_variant 13/17

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
TTNENST00000589042.5 linkuse as main transcriptc.57442A>G p.Met19148Val missense_variant 294/3635 NM_001267550.2 P1
TTN-AS1ENST00000659121.1 linkuse as main transcriptn.461T>C non_coding_transcript_exon_variant 2/13

Frequencies

GnomAD3 genomes
AF:
0.000395
AC:
60
AN:
152048
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000121
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000584
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.000188
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000706
Gnomad OTH
AF:
0.000478
GnomAD3 exomes
AF:
0.000496
AC:
123
AN:
248042
Hom.:
1
AF XY:
0.000461
AC XY:
62
AN XY:
134528
show subpopulations
Gnomad AFR exome
AF:
0.0000646
Gnomad AMR exome
AF:
0.0000581
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000393
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.000464
Gnomad NFE exome
AF:
0.000901
Gnomad OTH exome
AF:
0.000332
GnomAD4 exome
AF:
0.000695
AC:
1015
AN:
1461096
Hom.:
1
Cov.:
31
AF XY:
0.000643
AC XY:
467
AN XY:
726834
show subpopulations
Gnomad4 AFR exome
AF:
0.000209
Gnomad4 AMR exome
AF:
0.0000448
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.000202
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.000487
Gnomad4 NFE exome
AF:
0.000856
Gnomad4 OTH exome
AF:
0.000331
GnomAD4 genome
AF:
0.000394
AC:
60
AN:
152166
Hom.:
0
Cov.:
32
AF XY:
0.000242
AC XY:
18
AN XY:
74392
show subpopulations
Gnomad4 AFR
AF:
0.000120
Gnomad4 AMR
AF:
0.0000654
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.000585
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.000188
Gnomad4 NFE
AF:
0.000706
Gnomad4 OTH
AF:
0.000473
Alfa
AF:
0.000686
Hom.:
0
Bravo
AF:
0.000397
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.000778
AC:
3
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000603
AC:
5
ExAC
AF:
0.000430
AC:
52
EpiCase
AF:
0.000436
EpiControl
AF:
0.000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:11Benign:12
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:5Benign:6
Uncertain significance, criteria provided, single submitterresearchBiesecker Lab/Clinical Genomics Section, National Institutes of HealthJun 24, 2013- -
Likely benign, no assertion criteria providedclinical testingDiagnostic Laboratory, Department of Genetics, University Medical Center Groningen-- -
Uncertain significance, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenNov 30, 2016- -
Uncertain significance, criteria provided, single submitterclinical testingRevvity Omics, RevvityApr 25, 2022- -
Likely benign, no assertion criteria providedclinical testingClinical Genetics, Academic Medical Center-- -
Uncertain significance, criteria provided, single submitterclinical testingARUP Laboratories, Molecular Genetics and Genomics, ARUP LaboratoriesAug 24, 2023The TTN c.57442A>G; p.Met19148Val variant (rs188185141; ClinVar Variation ID: 191935) is rare in the general population (<0.2% allele frequency in the Genome Aggregation Database) and has been reported in individuals with hypertrophic cardiomyopathy and arrhythmogenic cardiomyopathy (Lopes 2013, Mates 2018). The clinical relevance of rare missense variants in this gene, which are identified on average once per individual sequenced in affected populations (Herman 2012), is not well understood. Yet, evidence suggests that the vast majority of such missense variants do not contribute to the clinical outcome of DCM (Begay 2015). Thus, the clinical significance of the p.Met19148Val variant cannot be determined with certainty. References: Lopes LR et al. Genetic complexity in hypertrophic cardiomyopathy revealed by high-throughput sequencing. J Med Genet. 2013 Apr;50(4):228-39. PMID: 23396983. Mates J et al. Role of copy number variants in sudden cardiac death and related diseases: genetic analysis and translation into clinical practice. Eur J Hum Genet. 2018 Jul;26(7):1014-1025. PMID: 29511324. Begay RL et al. Role of Titin Missense Variants in Dilated Cardiomyopathy. J Am Heart Assoc. 2015 Nov 13;4(11). PMID: 26567375. Herman DS et al. Truncations of titin causing dilated cardiomyopathy. N Engl J Med. 2012 Feb 16;366(7):619-28. PMID: 22335739. Linke WA and Hamdani N. Gigantic business: titin properties and function through thick and thin. Circ Res 2014; 114(6): 1052-1068. PMID: 24625729. -
Likely benign, criteria provided, single submitterclinical testingGeneDxApr 27, 2021- -
Likely benign, no assertion criteria providedclinical testingLaboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)-- -
Likely benign, no assertion criteria providedclinical testingClinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center-- -
Likely benign, no assertion criteria providedclinical testingGenome Diagnostics Laboratory, University Medical Center Utrecht-- -
Uncertain significance, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Sep 06, 2017- -
not specified Uncertain:1Benign:2
Uncertain significance, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineOct 10, 2017proposed classification - variant undergoing re-assessment, contact laboratory -
Benign, no assertion criteria providedclinical testingJoint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+-- -
Likely benign, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpMay 15, 2023Variant summary: TTN c.49738A>G (p.Met16580Val) results in a conservative amino acid change located in the A-band region of the encoded protein sequence. Three of four in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.0005 in 248042 control chromosomes, predominantly at a frequency of 0.0009 within the Non-Finnish European subpopulation in the gnomAD database, including 1 homozygotes. The observed variant frequency within Non-Finnish European control individuals in the gnomAD database is approximately 2 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 Non-Finnish European origin. c.49738A>G has been reported in the literature in individuals affected with Dilated Cardiomyopathy without strong evidence for causality. These reports do not provide unequivocal conclusions about association of the variant with Dilated Cardiomyopathy. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication have been ascertained in the context of this evaluation (PMID: 35207729). Multiple 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 (n=1), Likely Benign (n=3) and VUS (n=7). Based on the evidence outlined above, the variant was classified as likely benign. -
Autosomal recessive limb-girdle muscular dystrophy type 2J Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaApr 27, 2017This 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. -
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingInvitaeDec 14, 2017- -
Dilated cardiomyopathy 1G Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaApr 27, 2017This 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 submitterclinical testingIllumina Laboratory Services, IlluminaApr 27, 2017This 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. -
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 Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsOct 31, 2018- -
Cardiomyopathy Benign:1
Likely benign, criteria provided, single submitterclinical testingCHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern OntarioJan 03, 2020- -
Myopathy, myofibrillar, 9, with early respiratory failure Benign:1
Benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJul 18, 2017This 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. -
Tibial muscular dystrophy Benign:1
Benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJul 18, 2017This 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 submitterclinical testingAmbry GeneticsMay 06, 2020This 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: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.14
BayesDel_addAF
Benign
-0.38
T
BayesDel_noAF
Benign
-0.40
CADD
Benign
16
DANN
Benign
0.87
Eigen
Benign
-0.25
Eigen_PC
Benign
-0.032
FATHMM_MKL
Uncertain
0.87
D
LIST_S2
Uncertain
0.86
D;D;D;.;T;D;T
M_CAP
Benign
0.014
T
MetaRNN
Benign
0.029
T;T;T;T;T;T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
-0.32
.;.;.;N;.;.;N
MutationTaster
Benign
0.90
D;D;D;D;D;D
PrimateAI
Benign
0.41
T
PROVEAN
Uncertain
-2.5
N;D;.;.;D;D;.
REVEL
Benign
0.14
Sift
Benign
0.098
T;D;.;.;D;D;.
Polyphen
0.065
.;.;.;B;.;.;B
Vest4
0.33
MVP
0.22
MPC
0.086
ClinPred
0.021
T
GERP RS
4.9
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
2.1

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs188185141; hg19: chr2-179462367; API