2-178739374-C-T

Position:

chr2-178739374-C-T

Variant summary

Our verdict is Benign. Variant got -19 ACMG points: 1P and 20B. PP2BP4_StrongBP6_Very_StrongBS1BS2

The NM_001267550.2(TTN):c.13859G>A(p.Gly4620Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00223 in 1,613,882 control chromosomes in the GnomAD database, including 53 homozygotes. In-silico tool predicts a benign outcome for this variant. 12/17 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0018 ( 6 hom., cov: 32)

Exomes 𝑓: 0.0023 ( 47 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:20

Conservation

PhyloP100: 2.48

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:):

TTN-AS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -19 ACMG points.

PP2

Missense variant in gene, where missense usually causes diseases (based on misZ statistic), TTN. . Gene score misZ -1.1021 (greater than the threshold 3.09). Trascript score misZ 6.9794 (greater than threshold 3.09). GenCC has associacion of gene with dilated cardiomyopathy, tibial muscular dystrophy, early-onset myopathy with fatal cardiomyopathy, autosomal recessive centronuclear myopathy, hypertrophic cardiomyopathy, hypertrophic cardiomyopathy 9, TTN-related myopathy, dilated cardiomyopathy 1G, arrhythmogenic right ventricular cardiomyopathy, myopathy, myofibrillar, 9, with early respiratory failure, familial isolated dilated cardiomyopathy, childhood-onset progressive contractures-limb-girdle weakness-muscle dystrophy syndrome, autosomal recessive limb-girdle muscular dystrophy type 2J.

BP4

Computational evidence support a benign effect (MetaRNN=0.0029836297).

BP6

Variant 2-178739374-C-T is Benign according to our data. Variant chr2-178739374-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 47841.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178739374-C-T is described in Lovd as [Benign]. Variant chr2-178739374-C-T is described in Lovd as [Likely_benign].

BS1

Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.00183 (279/152298) while in subpopulation SAS AF= 0.0245 (118/4820). AF 95% confidence interval is 0.0209. There are 6 homozygotes in gnomad4. There are 161 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

BS2

High Homozygotes in GnomAd4 at 6 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.13859G>A	p.Gly4620Asp	missense_variant	48/363	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.13859G>A	p.Gly4620Asp	missense_variant	48/363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.00181

AC:

276

AN:

152180

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00183

Gnomad ASJ

AF:

0.000865

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.0238

Gnomad FIN

AF:

0.0000941

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00169

Gnomad OTH

AF:

0.00191

GnomAD3 exomes

AF:

0.00385

AC:

957

AN:

248522

Hom.:

AF XY:

0.00493

AC XY:

665

AN XY:

134804

show subpopulations

Gnomad AFR exome

AF:

0.000194

Gnomad AMR exome

AF:

0.000783

Gnomad ASJ exome

AF:

0.000896

Gnomad EAS exome

AF:

0.0000558

Gnomad SAS exome

AF:

0.0224

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00187

Gnomad OTH exome

AF:

0.00365

GnomAD4 exome

AF:

0.00227

AC:

3321

AN:

1461584

Hom.:

Cov.:

AF XY:

0.00291

AC XY:

2118

AN XY:

727074

show subpopulations

Gnomad4 AFR exome

AF:

0.000418

Gnomad4 AMR exome

AF:

0.000716

Gnomad4 ASJ exome

AF:

0.000842

Gnomad4 EAS exome

AF:

0.000176

Gnomad4 SAS exome

AF:

0.0215

Gnomad4 FIN exome

AF:

0.0000749

Gnomad4 NFE exome

AF:

0.00107

Gnomad4 OTH exome

AF:

0.00297

GnomAD4 genome

AF:

0.00183

AC:

279

AN:

152298

Hom.:

Cov.:

AF XY:

0.00216

AC XY:

161

AN XY:

74458

show subpopulations

Gnomad4 AFR

AF:

0.000241

Gnomad4 AMR

AF:

0.00183

Gnomad4 ASJ

AF:

0.000865

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.0245

Gnomad4 FIN

AF:

0.0000941

Gnomad4 NFE

AF:

0.00169

Gnomad4 OTH

AF:

0.00189

Alfa

AF:

0.00181

Hom.:

Bravo

AF:

0.00107

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.00130

AC:

ESP6500AA

AF:

0.000514

AC:

ESP6500EA

AF:

0.00193

AC:

ExAC

AF:

0.00442

AC:

534

Asia WGS

AF:

0.0130

AC:

AN:

3478

EpiCase

AF:

0.00267

EpiControl

AF:

0.00279

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:20

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:6

Benign, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -
Benign, criteria provided, single submitter	clinical testing	Athena Diagnostics	Nov 05, 2019	- -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Feb 08, 2016	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. -
Benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Sep 01, 2015	- -
Benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Feb 25, 2015	p.Gly4382Asp in exon 45B of TTN: This variant is not expected to have clinical s ignificance because it has been identified in 2.4% (392/16508) of South Asian ch romosomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute. org; dbSNP rs55857742). -

not provided

Benign:6

Benign, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Mar 12, 2020	- -
Likely benign, criteria provided, single submitter	not provided	Breakthrough Genomics, Breakthrough Genomics	-	- -
Likely benign, criteria provided, single submitter	research	Biesecker Lab/Clinical Genomics Section, National Institutes of Health	Jun 24, 2013	- -
Likely benign, no assertion criteria provided	clinical testing	Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)	-	- -
Likely benign, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Likely benign, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

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

Benign:1

Benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 31, 2024

- -

Cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

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

Nov 18, 2022

- -

Early-onset myopathy with fatal cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Tibial muscular dystrophy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Myopathy, myofibrillar, 9, with early respiratory failure

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Primary dilated cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

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

Feb 28, 2017

- -

Cardiovascular phenotype

Benign:1

Benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 06, 2016

This alteration is classified as 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

Benign

0.26

BayesDel_addAF

Benign

-0.30

BayesDel_noAF

Benign

-0.19

CADD

Benign

DANN

Benign

0.88

Eigen

Benign

0.11

Eigen_PC

Uncertain

0.24

FATHMM_MKL

Uncertain

0.83

LIST_S2

Benign

0.76

T;T;.;T;T;T

MetaRNN

Benign

0.0030

T;T;T;T;T;T

MetaSVM

Benign

-0.42

PrimateAI

Benign

0.33

PROVEAN

Uncertain

-3.4

D;.;.;D;D;.

REVEL

Uncertain

0.40

Sift

Benign

0.072

T;.;.;D;T;.

Vest4

0.18

MVP

0.46

MPC

0.11

ClinPred

0.012

GERP RS

4.1

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

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