chr2-178588699-C-T

Variant names:

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_001267550.2(TTN):c.63026G>A(p.Arg21009Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00117 in 1,613,182 control chromosomes in the GnomAD database, including 22 homozygotes. In-silico tool predicts a benign outcome for this variant. 11/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0065 ( 11 hom., cov: 32)

Exomes 𝑓: 0.00061 ( 11 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:17

Conservation

PhyloP100: 7.86

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 Benign. Variant got -20 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.010492563).

BP6

Variant 2-178588699-C-T is Benign according to our data. Variant chr2-178588699-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 47189.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178588699-C-T is described in Lovd as [Benign].

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00653 (994/152118) while in subpopulation AFR AF= 0.0226 (939/41526). AF 95% confidence interval is 0.0214. There are 11 homozygotes in gnomad4. There are 480 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

BS2

High Homozygotes in GnomAd4 at 11 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.63026G>A	p.Arg21009Gln	missense_variant	Exon 304 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.63026G>A	p.Arg21009Gln	missense_variant	Exon 304 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.00654

AC:

994

AN:

152000

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0227

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00269

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:

0.000118

Gnomad OTH

AF:

0.00287

GnomAD3 exomes

AF:

0.00161

AC:

401

AN:

248514

Hom.:

AF XY:

0.00122

AC XY:

165

AN XY:

134834

show subpopulations

Gnomad AFR exome

AF:

0.0239

Gnomad AMR exome

AF:

0.000667

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000444

Gnomad OTH exome

AF:

0.000498

GnomAD4 exome

AF:

0.000608

AC:

888

AN:

1461064

Hom.:

Cov.:

AF XY:

0.000506

AC XY:

368

AN XY:

726812

show subpopulations

Gnomad4 AFR exome

AF:

0.0220

Gnomad4 AMR exome

AF:

0.000962

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000405

Gnomad4 OTH exome

AF:

0.00106

GnomAD4 genome

AF:

0.00653

AC:

994

AN:

152118

Hom.:

Cov.:

AF XY:

0.00645

AC XY:

480

AN XY:

74366

show subpopulations

Gnomad4 AFR

AF:

0.0226

Gnomad4 AMR

AF:

0.00269

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000118

Gnomad4 OTH

AF:

0.00284

Alfa

AF:

0.00109

Hom.:

Bravo

AF:

0.00695

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.00

AC:

ESP6500AA

AF:

0.0220

AC:

ESP6500EA

AF:

0.000242

AC:

ExAC

AF:

0.00194

AC:

235

Asia WGS

AF:

0.000578

AC:

AN:

3476

EpiCase

AF:

0.0000546

EpiControl

AF:

0.00

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:17

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:9

Jul 31, 2024

Athena Diagnostics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+

Significance: Benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Genome Diagnostics Laboratory, University Medical Center Utrecht

Significance: Benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Clinical Genetics, Academic Medical Center

Significance: Benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

May 10, 2020

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

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

Significance: Benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Jul 09, 2014

GeneDx

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Aug 15, 2012

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Arg18441Gln in Exon 253 of TTN: This variant is not expected to have clinical si gnificance because it has been identified in 2.2% (68/3122) of African American chromosomes from a broad population by the NHLBI Exome Sequencing Project (http: //evs.gs.washington.edu/EVS; dbSNP rs72646851). -

Jun 24, 2013

Biesecker Lab/Clinical Genomics Section, National Institutes of Health

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: research

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Benign:1

Sep 10, 2021

Genome-Nilou Lab

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

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

Benign:1

Jan 30, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Cardiomyopathy

Benign:1

Jan 09, 2023

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

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Early-onset myopathy with fatal cardiomyopathy

Benign:1

Sep 10, 2021

Genome-Nilou Lab

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Tibial muscular dystrophy

Benign:1

Sep 10, 2021

Genome-Nilou Lab

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Myopathy, myofibrillar, 9, with early respiratory failure

Benign:1

Sep 10, 2021

Genome-Nilou Lab

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Heart failure;C0023976:Long QT syndrome;C0878544:Cardiomyopathy

Benign:1

Jun 03, 2019

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

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Cardiovascular phenotype

Benign:1

Sep 28, 2017

Ambry Genetics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

General population or subpopulation frequency is too high to be a pathogenic mutation based on disease/syndrome prevalence and penetrance -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.24

BayesDel_addAF

Benign

-0.39

BayesDel_noAF

Benign

-0.32

CADD

Benign

DANN

Benign

0.97

Eigen

Pathogenic

0.82

Eigen_PC

Pathogenic

0.85

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.95

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

MetaRNN

Benign

0.010

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

MetaSVM

Benign

-0.66

MutationAssessor

Benign

1.9

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

PrimateAI

Benign

0.45

PROVEAN

Uncertain

-2.9

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

REVEL

Uncertain

0.30

Sift

Uncertain

0.011

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

Polyphen

1.0

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

Vest4

0.41

MVP

0.28

MPC

0.50

ClinPred

0.018

GERP RS

6.2

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