2-178576727-C-T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.

The NM_001267550.2(TTN):c.69517G>A(p.Gly23173Arg) variant causes a missense change. The variant allele was found at a frequency of 0.0000267 in 1,613,378 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. G23173G) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000027 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 6.12

Publications

0 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:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.69517G>A	p.Gly23173Arg	missense_variant	Exon 325 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.69517G>A	p.Gly23173Arg	missense_variant	Exon 325 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

151998

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.00

GnomAD2 exomes

AF:

0.0000161

AC:

AN:

248556

AF XY:

0.0000223

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000356

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000274

AC:

AN:

1461380

Hom.:

Cov.:

AF XY:

0.0000316

AC XY:

AN XY:

726976

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33462

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26120

East Asian (EAS)

AF:

0.00

AC:

AN:

39674

South Asian (SAS)

AF:

0.00

AC:

AN:

86244

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53398

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5762

European-Non Finnish (NFE)

AF:

0.0000351

AC:

AN:

1111644

Other (OTH)

AF:

0.0000166

AC:

AN:

60354

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.501

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome 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

GnomAD4 genome

AF:

0.0000197

AC:

AN:

151998

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74228

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41402

American (AMR)

AF:

0.00

AC:

AN:

15256

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5146

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10608

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000441

AC:

AN:

67974

Other (OTH)

AF:

0.00

AC:

AN:

2086

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.508

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:

0.0000602

Hom.:

Bravo

AF:

0.0000151

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000519

AC:

ExAC

AF:

0.00000827

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Oct 26, 2016

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Dec 27, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); Missense variant in a gene in which most reported pathogenic variants are truncating/loss of function; Has not been previously published as pathogenic or benign to our knowledge; Located in the A-band, a region of TTN for which truncating variants are significantly associated with autosomal dominant cardiomyopathy and also with autosomal recessive skeletal myopathies (PMID: 22335739, 32778822) -

not specified

Uncertain:1

Aug 29, 2018

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.Gly20605Arg variant in TTN has not been previously reported in individuals with cardiomyopathy but has been identified in 5/126040 European chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org). Thi s variant has also been reported in ClinVar (Variation ID 467420). Computational prediction tools and conservation analysis suggest that the p.Gly20605Arg varia nt may impact the protein, though this information is not predictive enough to d etermine pathogenicity. In summary, the clinical significance of the p.Gly20605A rg variant is uncertain. ACMG/AMP Criteria applied: PP3. -

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

Uncertain:1

Dec 21, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Cardiovascular phenotype

Uncertain:1

Mar 18, 2019

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.G14108R variant (also known as c.42322G>A), located in coding exon 152 of the TTN gene, results from a G to A substitution at nucleotide position 42322. The glycine at codon 14108 is replaced by arginine, an amino acid with dissimilar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be probably damaging by PolyPhen in silico analyses. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.77

BayesDel_addAF

Uncertain

0.070

BayesDel_noAF

Uncertain

-0.030

CADD

Benign

(source)

DANN

Benign

0.95

Eigen

Pathogenic

0.82

Eigen_PC

Pathogenic

0.77

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.97

D;D;D;.;D;D;D

M_CAP

Benign

0.048

MetaRNN

Uncertain

0.54

D;D;D;D;D;D;D

MetaSVM

Uncertain

-0.0053

MutationAssessor

Uncertain

2.9

.;.;.;M;.;.;M

PhyloP100

6.1

PrimateAI

Uncertain

0.67

PROVEAN

Pathogenic

-6.3

D;D;.;.;D;D;.

REVEL

Uncertain

0.50

Sift

Uncertain

0.0020

D;D;.;.;D;D;.

Polyphen

1.0

.;.;.;D;.;.;D

Vest4

0.57

MutPred

0.72

.;.;.;Gain of catalytic residue at G21532 (P = 0.0043);.;.;Gain of catalytic residue at G21532 (P = 0.0043);

MVP

0.59

MPC

0.48

ClinPred

0.53

GERP RS

4.8

Mutation Taster

=77/23

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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