chr2-178651962-C-T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BP6

The NM_001267550.2(TTN):c.39301G>A(p.Glu13101Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000401 in 1,610,180 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E13101Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00021 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00042 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6B:5

Conservation

PhyloP100: 0.679

Publications

6 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:

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:

LOC124906100 (HGNC:):

LOC124906100 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -1 ACMG points.

BP6

Variant 2-178651962-C-T is Benign according to our data. Variant chr2-178651962-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 46924.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.39301G>A	p.Glu13101Lys	missense_variant	Exon 205 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.39301G>A	p.Glu13101Lys	missense_variant	Exon 205 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.000211

AC:

AN:

151890

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000121

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000656

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000208

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000368

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000269

AC:

AN:

241906

AF XY:

0.000221

show subpopulations

Gnomad AFR exome

AF:

0.000266

Gnomad AMR exome

AF:

0.0000593

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000470

Gnomad NFE exome

AF:

0.000450

Gnomad OTH exome

AF:

0.000170

GnomAD4 exome

AF:

0.000420

AC:

613

AN:

1458172

Hom.:

Cov.:

AF XY:

0.000412

AC XY:

299

AN XY:

725030

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33416

American (AMR)

AF:

0.0000452

AC:

AN:

44210

Ashkenazi Jewish (ASJ)

AF:

0.0000384

AC:

AN:

26042

East Asian (EAS)

AF:

0.00

AC:

AN:

39428

South Asian (SAS)

AF:

0.0000933

AC:

AN:

85708

European-Finnish (FIN)

AF:

0.0000564

AC:

AN:

53210

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5758

European-Non Finnish (NFE)

AF:

0.000523

AC:

581

AN:

1110196

Other (OTH)

AF:

0.000282

AC:

AN:

60204

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.471

Heterozygous variant carriers

101

134

168

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

120

<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:

0.000211

AC:

AN:

152008

Hom.:

Cov.:

AF XY:

0.000135

AC XY:

AN XY:

74292

show subpopulations

African (AFR)

AF:

0.000121

AC:

AN:

41472

American (AMR)

AF:

0.0000655

AC:

AN:

15266

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5158

South Asian (SAS)

AF:

0.000208

AC:

AN:

4812

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10554

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000368

AC:

AN:

67962

Other (OTH)

AF:

0.00

AC:

AN:

2106

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:

0.000314

Hom.:

Bravo

AF:

0.000155

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.000519

AC:

ESP6500AA

AF:

0.000536

AC:

ESP6500EA

AF:

0.000244

AC:

ExAC

AF:

0.000240

AC:

Asia WGS

AF:

0.000866

AC:

AN:

3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6Benign:5

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:5Benign:1

Mar 29, 2021

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant is associated with the following publications: (PMID: 23396983, 24503780) -

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

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

May 22, 2019

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

May 14, 2018

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The TTN: c.31999G>A; p.Glu10667Lys variant is rare in the general population (<1% allele frequency in the Genome Aggregation Database) and have 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. While the clinical significance of such variants is considered uncertain, evidence suggests that the vast majority of missense variants do not contribute to the clinical outcome of DCM (Begay 2015). Given the available evidence, the clinical significance of the p.Arg13618Leu and p.Ala7671Gly variants cannot be determined with certainty. -

Sep 01, 2017

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Clinical Genetics, Academic Medical Center

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

not specified

Benign:3

Dec 09, 2024

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.31999G>A (p.Glu10667Lys) results in a conservative amino acid change located in the I-band region of the encoded protein sequence. Four of four in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00027 in 241906 control chromosomes, predominantly at a frequency of 0.00045 within the Non-Finnish European subpopulation in the gnomAD database. The observed variant frequency within Non-Finnish European control individuals in the gnomAD database is approximately 1.2 fold of the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Dilated Cardiomyopathy phenotype (0.00039). c.31999G>A has been reported in the literature in individuals affected with Dilated Cardiomyopathy (Pugh_2014) and Hypertrophic Cardiomyopathy (Lopes_2013) . These reports do not provide unequivocal conclusions about association of the variant with Dilated Cardiomyopathy. Co-occurrence with another pathogenic variant has been reported (MYH7 c.2722C>G, p.Leu908Val, internal testing), providing supporting evidence for a benign role. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 23396983, 24503780). ClinVar contains an entry for this variant (Variation ID: 46924). Based on the evidence outlined above, the variant was classified as likely benign. -

Mar 30, 2021

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.Glu10667Lys variant in TTN is classified as likely benign because it has been identified in 0.04% (55/124348) of European chromosomes by gnomAD (http://gnomad.broadinstitute.org). ACMG/AMP Criteria applied: BS1. -

Apr 09, 2025

Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

BS1;BP1 -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G

Uncertain:1

Dec 19, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Cardiomyopathy

Benign:1

Mar 03, 2023

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

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.14

BayesDel_addAF

Benign

-0.30

BayesDel_noAF

Benign

-0.34

CADD

Benign

(source)

DANN

Benign

0.87

Eigen

Benign

-0.20

Eigen_PC

Benign

-0.16

FATHMM_MKL

Benign

0.23

LIST_S2

Benign

0.67

T;T;.;T

M_CAP

Benign

0.053

MetaRNN

Benign

0.059

T;T;T;T

MetaSVM

Benign

-0.58

MutationAssessor

Uncertain

2.7

.;.;M;M

PhyloP100

0.68

PrimateAI

Uncertain

0.55

PROVEAN

Benign

-1.8

N;.;.;.

REVEL

Benign

0.15

Sift

Benign

0.074

T;.;.;.

Polyphen

0.011

.;.;B;B

Vest4

0.25

MVP

0.41

MPC

0.095

ClinPred

0.028

GERP RS

5.3

PromoterAI

-0.0096

Neutral

(source)

Mutation Taster

=91/9

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.24

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.24

Position offset: -3

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