chr2-178601716-G-C

Variant names:

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 0P and 3B. BP4_ModerateBP6

The NM_001267550.2(TTN):c.55374C>G(p.Ser18458Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00064 in 1,610,360 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 12/19 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 0.00060 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00064 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 1.57

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 made for transcript

Verdict is Likely_benign. Variant got -3 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.06986305).

BP6

Variant 2-178601716-G-C is Benign according to our data. Variant chr2-178601716-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 165969.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=5, Uncertain_significance=6}. Variant chr2-178601716-G-C is described in Lovd as [Likely_benign].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.55374C>G	p.Ser18458Arg	missense_variant	Exon 286 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.55374C>G	p.Ser18458Arg	missense_variant	Exon 286 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.000605

AC:

AN:

152042

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000193

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:

0.000471

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00116

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000391

AC:

AN:

245648

Hom.:

AF XY:

0.000345

AC XY:

AN XY:

133202

show subpopulations

Gnomad AFR exome

AF:

0.000130

Gnomad AMR exome

AF:

0.0000588

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000336

Gnomad FIN exome

AF:

0.000702

Gnomad NFE exome

AF:

0.000664

Gnomad OTH exome

AF:

0.000336

GnomAD4 exome

AF:

0.000644

AC:

939

AN:

1458200

Hom.:

Cov.:

AF XY:

0.000625

AC XY:

453

AN XY:

725164

show subpopulations

Gnomad4 AFR exome

AF:

0.0000902

Gnomad4 AMR exome

AF:

0.0000452

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000117

Gnomad4 FIN exome

AF:

0.000808

Gnomad4 NFE exome

AF:

0.000768

Gnomad4 OTH exome

AF:

0.000615

GnomAD4 genome

AF:

0.000605

AC:

AN:

152160

Hom.:

Cov.:

AF XY:

0.000511

AC XY:

AN XY:

74380

show subpopulations

Gnomad4 AFR

AF:

0.000192

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.000471

Gnomad4 NFE

AF:

0.00116

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000759

Hom.:

Bravo

AF:

0.000525

TwinsUK

AF:

0.000539

AC:

ALSPAC

AF:

0.000519

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.00122

AC:

ExAC

AF:

0.000331

AC:

EpiCase

AF:

0.00126

EpiControl

AF:

0.000713

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6Benign:5

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:4Benign:2

Jun 24, 2013

Biesecker Lab/Clinical Genomics Section, National Institutes of Health

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: research

- -

Jul 31, 2015

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 17, 2022

Mayo Clinic Laboratories, Mayo Clinic

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Oct 05, 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) -

Nov 01, 2023

CeGaT Center for Human Genetics Tuebingen

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 22, 2023

Revvity Omics, Revvity

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not specified

Uncertain:1Benign:1

Aug 27, 2014

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 Ser15890Arg var iant in TTN has not been previously reported in individuals with cardiomyopathy, but has been identified in 0.1% (10/8194) of European American chromosomes by t he NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS/; dbSNP rs20 0550947). Computational prediction tools and conservation analysis do not provid e strong support for or against an impact to the protein. In summary, while the clinical significance of the Ser15890Arg variant is uncertain, its frequency sug gests that it is more likely to be benign. -

Aug 30, 2021

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.47670C>G (p.Ser15890Arg) results in a non-conservative amino acid change located in the A-band domain of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00041 in 277010 control chromosomes, predominantly at a frequency of 0.0007 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 2 fold of the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Dilated Cardiomyopathy phenotype (0.00039), strongly suggesting that the variant is a benign polymorphism found primarily in populations of Non-Finnish European origin. c.47670C>G has been reported in the literature in one individual affected with Dilated Cardiomyopathy (Roggenbuck_2019). The report does not provide unequivocal conclusions about association of the variant with Dilated Cardiomyopathy. Additionally, one co-occurrence with another pathogenic variant has been reported (exons 346-362 deletion; Roggenbuck_2019), providing supporting evidence for a benign role. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Four ClinVar submitters (evaluation after 2014) cite the variant as uncertain significance (n=3) and likely benign (n=1). Based on the evidence outlined above, the variant was classified as likely benign. -

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

Uncertain:1

Dec 29, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Cardiomyopathy

Benign:1

Mar 16, 2020

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

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Cardiovascular phenotype

Benign:1

Jan 02, 2020

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.64

BayesDel_addAF

Benign

-0.29

BayesDel_noAF

Benign

-0.27

CADD

Benign

DANN

Benign

0.74

Eigen

Benign

0.052

Eigen_PC

Benign

0.028

FATHMM_MKL

Uncertain

0.94

LIST_S2

Uncertain

0.91

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

M_CAP

Benign

0.028

MetaRNN

Benign

0.070

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

MetaSVM

Benign

-0.76

MutationAssessor

Benign

1.1

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

PrimateAI

Uncertain

0.61

PROVEAN

Uncertain

-3.0

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

REVEL

Benign

0.27

Sift

Benign

0.17

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

Polyphen

0.99

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

Vest4

0.51

MutPred

0.47

.;.;.;Gain of MoRF binding (P = 0.0184);.;.;Gain of MoRF binding (P = 0.0184);

MVP

0.21

MPC

0.43

ClinPred

0.13

GERP RS

1.1

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over