2-178611260-T-C

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_001267550.2(TTN):c.50869A>G(p.Ile16957Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000018 in 1,612,048 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I16957T) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000019 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 1.81

Publications

1 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: Likely_benign. The variant received -2 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.11790097).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.50869A>G	p.Ile16957Val	missense_variant	Exon 270 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.50869A>G	p.Ile16957Val	missense_variant	Exon 270 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

151970

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000162

AC:

AN:

246754

AF XY:

0.0000224

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:

0.0000467

Gnomad NFE exome

AF:

0.0000179

Gnomad OTH exome

AF:

0.000167

GnomAD4 exome

AF:

0.0000192

AC:

AN:

1460078

Hom.:

Cov.:

AF XY:

0.0000165

AC XY:

AN XY:

726296

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33406

American (AMR)

AF:

0.00

AC:

AN:

44566

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26100

East Asian (EAS)

AF:

0.00

AC:

AN:

39428

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86060

European-Finnish (FIN)

AF:

0.0000188

AC:

AN:

53284

Middle Eastern (MID)

AF:

0.000174

AC:

AN:

5752

European-Non Finnish (NFE)

AF:

0.0000207

AC:

AN:

1111214

Other (OTH)

AF:

0.0000166

AC:

AN:

60268

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.470

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.00000658

AC:

AN:

151970

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74212

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41424

American (AMR)

AF:

0.00

AC:

AN:

15244

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5144

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10626

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

67920

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000496

Hom.:

Bravo

AF:

0.0000264

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000122

AC:

ExAC

AF:

0.0000166

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Nov 21, 2023

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Apr 03, 2017

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not specified

Uncertain:1

May 28, 2014

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The Ile14389Val variant in TTN has not been previously reported in individuals w ith cardiomyopathy, but has been identified in 1/8218 European American chromoso mes by the NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS/; db SNP rs372013419). Isoleucine (Ile) at position 14389 is not well conserved in ev olution and 3 species (alligator, turtle, and lizard) carry a valine (Val) at th is position, raising the possibility that this change may be tolerated. In summa ry, the clinical significance of the Ile14389Val variant is uncertain. -

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

Uncertain:1

Jul 24, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Dilated cardiomyopathy 1G;C1861065:Hypertrophic cardiomyopathy 9

Uncertain:1

May 15, 2023

New York Genome Center

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

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

Oct 31, 2018

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.080

BayesDel_addAF

Benign

-0.15

BayesDel_noAF

Benign

-0.39

CADD

Benign

(source)

DANN

Benign

0.89

Eigen

Benign

-0.0062

Eigen_PC

Benign

0.17

FATHMM_MKL

Uncertain

0.95

LIST_S2

Benign

0.81

T;T;T;.;T;T;T

M_CAP

Benign

0.026

MetaRNN

Benign

0.12

T;T;T;T;T;T;T

MetaSVM

Benign

-0.70

MutationAssessor

Benign

1.9

.;.;.;L;.;.;L

PhyloP100

1.8

PrimateAI

Benign

0.35

PROVEAN

Benign

-0.75

N;N;.;.;N;N;.

REVEL

Benign

0.12

Sift

Benign

0.066

T;T;.;.;T;T;.

Polyphen

0.0050

.;.;.;B;.;.;B

Vest4

0.24

MVP

0.33

MPC

0.073

ClinPred

0.065

GERP RS

5.9

Mutation Taster

=93/7

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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2-178611260-T-C

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over