chr2-178689852-C-T

Variant names:

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_StrongBP6BS1

The NM_001267550.2(TTN):c.31807G>A(p.Val10603Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000178 in 1,613,094 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: 𝑓 0.00081 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00011 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:7

Conservation

PhyloP100: 1.59

Publications

5 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 links:

LOC124907912 (HGNC:):

LOC124907912 links:

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]

TTN-AS1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -9 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.014819056).

BP6

Variant 2-178689852-C-T is Benign according to our data. Variant chr2-178689852-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 193962.

BS1

Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000808 (123/152218) while in subpopulation AFR AF = 0.00267 (111/41542). AF 95% confidence interval is 0.00227. There are 0 homozygotes in GnomAd4. There are 61 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.31807G>A	p.Val10603Ile	missense_variant	Exon 122 of 363	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 link	c.31807G>A	p.Val10603Ile	missense_variant	Exon 122 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.000802

AC:

122

AN:

152100

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00266

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000393

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:

0.0000441

Gnomad OTH

AF:

0.00143

GnomAD2 exomes

AF:

0.000197

AC:

AN:

248810

AF XY:

0.000163

show subpopulations

Gnomad AFR exome

AF:

0.00233

Gnomad AMR exome

AF:

0.000174

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000532

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000112

AC:

164

AN:

1460876

Hom.:

Cov.:

AF XY:

0.000113

AC XY:

AN XY:

726686

show subpopulations

African (AFR)

AF:

0.00272

AC:

AN:

33430

American (AMR)

AF:

0.000157

AC:

AN:

44616

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26106

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39656

South Asian (SAS)

AF:

0.0000465

AC:

AN:

86034

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53392

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.0000360

AC:

AN:

1111546

Other (OTH)

AF:

0.000331

AC:

AN:

60332

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.466

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

<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:

0.000808

AC:

123

AN:

152218

Hom.:

Cov.:

AF XY:

0.000820

AC XY:

AN XY:

74434

show subpopulations

African (AFR)

AF:

0.00267

AC:

111

AN:

41542

American (AMR)

AF:

0.000392

AC:

AN:

15292

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5178

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10586

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000441

AC:

AN:

68008

Other (OTH)

AF:

0.00142

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.505

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.000294

Hom.:

Bravo

AF:

0.000858

ESP6500AA

AF:

0.00191

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000240

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.0000546

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign:7

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2Benign:3

Dec 15, 2020

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Clinical Genetics, Academic Medical Center

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Oct 23, 2014

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Mar 03, 2022

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The TTN c.28075G>A; p.Val9359Ile variant (rs139790668; ClinVar Variation ID: 193962) is rare in the general population (<0.2% allele frequency in the Genome Aggregation Database) and has not been reported in the medical literature in association with dilated cardiomyopathy (DCM) or other TTN-related disease. 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.Val9359Ile variant cannot be determined with certainty." -

not specified

Uncertain:1Benign:1

Jan 28, 2015

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant classified as Uncertain Significance - Favor Benign. The p.Val9359Ile in TTN has not been previously reported in individuals with cardiomyopathy, but ha s been identified in 0.2% (21/9972) of African chromosomes by the Exome Aggregat ion Consortium (ExAC, http://exac.broadinstitute.org; dbSNP rs139790668). Comput ational prediction tools and conservation analysis suggest that this variant may not impact the protein, though this information is not predictive enough to rul e out pathogenicity. In summary, while the clinical significance of the p.Val93 59Ile variant is uncertain, its frequency suggests that it is more likely to be benign. -

Apr 18, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: TTN c.28075G>A (p.Val9359Ile) results in a conservative amino acid change in the encoded protein sequence. Two of two in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.0002 in 248810 control chromosomes, predominantly at a frequency of 0.0023 within the African or African-American subpopulation in the gnomAD database. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 5.89 fold of the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Autosomal Recessive Titinopathy phenotype (0.00039). To our knowledge, no occurrence of c.28075G>A in individuals affected with Autosomal Recessive Titinopathy and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 193962). Based on the evidence outlined above, the variant was classified as likely benign. -

TTN-related disorder

Benign:1

Jan 31, 2022

PreventionGenetics, part of Exact Sciences

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

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

Feb 02, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Cardiomyopathy

Benign:1

Jun 25, 2020

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.096

BayesDel_addAF

Benign

-0.44

BayesDel_noAF

Benign

-0.40

CADD

Benign

(source)

DANN

Uncertain

0.99

DEOGEN2

Benign

0.021

.;.;.;.;T

Eigen

Uncertain

0.38

Eigen_PC

Uncertain

0.47

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Benign

0.69

T;T;.;T;T

M_CAP

Benign

0.014

MetaRNN

Benign

0.015

T;T;T;T;T

MetaSVM

Benign

-0.40

PhyloP100

1.6

PrimateAI

Benign

0.38

PROVEAN

Benign

-0.50

N;.;.;.;N

REVEL

Benign

0.20

Sift

Benign

0.11

T;.;.;.;D

Polyphen

0.011

.;.;B;B;.

Vest4

0.26

MVP

0.59

MPC

0.071

ClinPred

0.025

GERP RS

5.5

Mutation Taster

=91/9

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

Details are displayed if max score is > 0.2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over