NM_001267550.2:c.21548G>A

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6

The NM_001267550.2(TTN):c.21548G>A(p.Cys7183Tyr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000721 in 1,613,390 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 11/19 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 0.00047 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00075 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:10B:8

Conservation

PhyloP100: 3.41

Publications

10 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:

ENSG00000267784 (HGNC:):

ENSG00000267784 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: Likely_benign. The variant received -3 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.07189745).

BP6

Variant 2-178723552-C-T is Benign according to our data. Variant chr2-178723552-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 178242.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.21548G>A	p.Cys7183Tyr	missense_variant	Exon 74 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.21548G>A	p.Cys7183Tyr	missense_variant	Exon 74 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.000473

AC:

AN:

152110

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000121

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:

0.000882

Gnomad OTH

AF:

0.000478

GnomAD2 exomes

AF:

0.000415

AC:

103

AN:

248348

AF XY:

0.000475

show subpopulations

Gnomad AFR exome

AF:

0.000129

Gnomad AMR exome

AF:

0.000494

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000465

Gnomad NFE exome

AF:

0.000658

Gnomad OTH exome

AF:

0.000499

GnomAD4 exome

AF:

0.000747

AC:

1092

AN:

1461162

Hom.:

Cov.:

AF XY:

0.000729

AC XY:

530

AN XY:

726840

show subpopulations

African (AFR)

AF:

0.0000897

AC:

AN:

33450

American (AMR)

AF:

0.000604

AC:

AN:

44682

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26118

East Asian (EAS)

AF:

0.00

AC:

AN:

39654

South Asian (SAS)

AF:

0.000371

AC:

AN:

86218

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53348

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.000905

AC:

1006

AN:

1111596

Other (OTH)

AF:

0.000398

AC:

AN:

60332

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.470

Heterozygous variant carriers

136

203

271

339

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

120

160

200

<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:

0.000473

AC:

AN:

152228

Hom.:

Cov.:

AF XY:

0.000403

AC XY:

AN XY:

74426

show subpopulations

African (AFR)

AF:

0.000120

AC:

AN:

41558

American (AMR)

AF:

0.000393

AC:

AN:

15278

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5166

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10620

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000883

AC:

AN:

67988

Other (OTH)

AF:

0.000473

AC:

AN:

2116

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.515

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:

0.000684

Hom.:

Bravo

AF:

0.000552

TwinsUK

AF:

0.000809

AC:

ALSPAC

AF:

0.00104

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.00122

AC:

ExAC

AF:

0.000348

AC:

EpiCase

AF:

0.000982

EpiControl

AF:

0.000831

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:10Benign:8

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:7Benign:3

Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

May 22, 2023

Mayo Clinic Laboratories, Mayo Clinic

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Oct 05, 2023

Revvity Omics, Revvity

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Nov 06, 2020

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant is associated with the following publications: (PMID: 23861362, 28771489) -

Jun 24, 2013

Biesecker Lab/Clinical Genomics Section, National Institutes of Health

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:research

- -

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

- -

Jan 19, 2018

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Dec 01, 2021

CeGaT Center for Human Genetics Tuebingen

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

- -

Jan 04, 2021

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The TTN c.21548G>A; p.Cys7183Tyr variant (rs189951108; ClinVar Variation ID: 178242) 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.Cys7183Tyr variant cannot be determined with certainty. Begay RL et al. Role of Titin Missense Variants in Dilated Cardiomyopathy. J Am Heart Assoc. 2015 Nov 13;4(11). Herman DS et al. Truncations of titin causing dilated cardiomyopathy. N Engl J Med. 2012 Feb 16;366(7):619-28. Linke WA and Hamdani N. Gigantic business: titin properties and function through thick and thin. Circ Res 2014; 114(6): 1052-1068. -

not specified

Uncertain:1Benign:2

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

- -

Sep 12, 2017

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.Cys5939Tyr variant in TTN has been identified by our laboratory in 1 indiv idual with RCM and 1 with HCM; however, both individuals harbor pathogenic varia nts in other genes responsible for their symptoms. This variant has been identif ied in 76/126152 of European chromosomes by the Genome Aggregation Database (gno mAD, http://gnomad.broadinstitute.org/; dbSNP rs189951108) and has been reported in ClinVar (Variation ID: 178242). Computational prediction tools and conservat ion analysis suggest that the p.Cys5939Tyr variant may impact the protein, thoug h this information is not predictive enough to determine pathogenicity. In summa ry, the clinical significance of the p.Cys5939Tyr variant is uncertain. -

May 28, 2024

Athena Diagnostics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

TTN-related disorder

Uncertain:1

Apr 25, 2023

PreventionGenetics, part of Exact Sciences

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The TTN c.21548G>A variant is predicted to result in the amino acid substitution p.Cys7183Tyr. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.060% of alleles in individuals of European (Non-Finnish) descent in gnomAD (http://gnomad.broadinstitute.org/variant/2-179588279-C-T). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

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

Uncertain:1

Nov 17, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Arrhythmogenic right ventricular cardiomyopathy

Benign:1

Apr 09, 2019

Center for Advanced Laboratory Medicine, UC San Diego Health, University of California San Diego

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Cardiomyopathy

Benign:1

May 16, 2023

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

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Skeletal dysplasia

Benign:1

Feb 05, 2020

Cambridge Genomics Laboratory, East Genomic Laboratory Hub, NHS Genomic Medicine Service

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

0.31

BayesDel_addAF

Benign

-0.23

BayesDel_noAF

Benign

-0.21

CADD

Benign

(source)

DANN

Benign

0.95

Eigen

Uncertain

0.51

Eigen_PC

Uncertain

0.58

FATHMM_MKL

Uncertain

0.96

LIST_S2

Benign

0.77

T;T;.;T

M_CAP

Benign

0.026

MetaRNN

Benign

0.072

T;T;T;T

MetaSVM

Benign

-0.42

PhyloP100

3.4

PrimateAI

Pathogenic

0.85

PROVEAN

Uncertain

-4.4

D;.;.;.

REVEL

Uncertain

0.34

Sift

Benign

1.0

T;.;.;.

Polyphen

1.0

.;.;D;D

Vest4

0.53

MVP

0.74

MPC

0.59

ClinPred

0.085

GERP RS

6.2

Mutation Taster

=66/34

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.040

Details are displayed if max score is > 0.2

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

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

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