rs72647870

Positions:

Variant summary

Our verdict is Benign. Variant got -12 ACMG points: 1P and 13B. PP2BP4_StrongBP6BS1BS2

The NM_001267550.2(TTN):c.3409G>C(p.Gly1137Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00302 in 1,613,956 control chromosomes in the GnomAD database, including 10 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0023 ( 1 hom., cov: 33)

Exomes 𝑓: 0.0031 ( 9 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:15

Conservation

PhyloP100: 7.87

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:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -12 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=0.017946422).

BP6

Variant 2-178781235-C-G is Benign according to our data. Variant chr2-178781235-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 46949.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=9, Benign=6, Uncertain_significance=1}. Variant chr2-178781235-C-G is described in Lovd as [Likely_benign]. Variant chr2-178781235-C-G is described in Lovd as [Benign].

BS1

Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.00229 (349/152254) while in subpopulation NFE AF= 0.00385 (262/68018). AF 95% confidence interval is 0.00347. There are 1 homozygotes in gnomad4. There are 164 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

BS2

High Homozygotes in GnomAdExome4 at 9 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.3409G>C	p.Gly1137Arg	missense_variant	21/363	ENST00000589042.5	NP_001254479.2
TTN	NM_133379.5 linkuse as main transcript	c.3409G>C	p.Gly1137Arg	missense_variant	21/46	ENST00000360870.10	NP_596870.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.3409G>C	p.Gly1137Arg	missense_variant	21/363	5	NM_001267550.2	ENSP00000467141	P1
TTN	ENST00000360870.10 linkuse as main transcript	c.3409G>C	p.Gly1137Arg	missense_variant	21/46	5	NM_133379.5	ENSP00000354117		Q8WZ42-6

Frequencies

GnomAD3 genomes

AF:

0.00229

AC:

349

AN:

152136

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000362

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000982

Gnomad ASJ

AF:

0.00346

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00387

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.00385

Gnomad OTH

AF:

0.00144

GnomAD3 exomes

AF:

0.00215

AC:

541

AN:

251114

Hom.:

AF XY:

0.00204

AC XY:

277

AN XY:

135736

show subpopulations

Gnomad AFR exome

AF:

0.000308

Gnomad AMR exome

AF:

0.000665

Gnomad ASJ exome

AF:

0.00179

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00407

Gnomad NFE exome

AF:

0.00347

Gnomad OTH exome

AF:

0.00196

GnomAD4 exome

AF:

0.00309

AC:

4520

AN:

1461702

Hom.:

Cov.:

AF XY:

0.00307

AC XY:

2229

AN XY:

727156

show subpopulations

Gnomad4 AFR exome

AF:

0.000418

Gnomad4 AMR exome

AF:

0.000671

Gnomad4 ASJ exome

AF:

0.00168

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00416

Gnomad4 NFE exome

AF:

0.00362

Gnomad4 OTH exome

AF:

0.00296

GnomAD4 genome

AF:

0.00229

AC:

349

AN:

152254

Hom.:

Cov.:

AF XY:

0.00220

AC XY:

164

AN XY:

74448

show subpopulations

Gnomad4 AFR

AF:

0.000361

Gnomad4 AMR

AF:

0.000981

Gnomad4 ASJ

AF:

0.00346

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00387

Gnomad4 NFE

AF:

0.00385

Gnomad4 OTH

AF:

0.00142

Alfa

AF:

0.00313

Hom.:

Bravo

AF:

0.00191

TwinsUK

AF:

0.00297

AC:

ALSPAC

AF:

0.00259

AC:

ESP6500AA

AF:

0.000454

AC:

ESP6500EA

AF:

0.00430

AC:

ExAC

AF:

0.00211

AC:

256

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.00316

EpiControl

AF:

0.00308

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:15

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Benign:5

Benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Aug 05, 2021	Variant summary: TTN c.3409G>C (p.Gly1137Arg) results in a non-conservative amino acid change located in the near Z-disk region of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.0022 in 395852 control chromosomes in the gnomAD database (v2.1 and v3.1 datasets), including 1 homozygote. The observed variant frequency is approximately 5.75 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 benign. c.3409G>C has been reported in the literature in individuals affected with individuals affected with hypertrophic cardiomyopathy and sudden unexplained death, however in at least one of these patients co-occurring potentially pathogenic variant(s) could explain the phenotype (Lopes_2013, Campuzano_2015). These reports do not support the association of the variant with Dilated Cardiomyopathy. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Eight other submitters have provided clinical-significance assessments for this variant in ClinVar after 2014 without evidence for independent evaluation, and classified the variant as VUS (1x), likely benign (6x) / benign (1x). Based on the evidence outlined above, the variant was classified as benign. -
Likely benign, criteria provided, single submitter	clinical testing	PreventionGenetics, part of Exact Sciences	-	- -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Jan 13, 2017	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. -
Likely benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Dec 30, 2014	p.Gly1137Arg in exon 21 of TTN: This variant is not expected to have clinical si gnificance because it has been identified in 0.3% (230/67514) of European chromo somes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; dbSNP rs72647870). -
Likely benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jun 11, 2015	- -

not provided

Benign:2

Likely benign, criteria provided, single submitter	research	Biesecker Lab/Clinical Genomics Section, National Institutes of Health	Jun 24, 2013	- -
Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Aug 01, 2024	TTN: BS2 -

Early-onset myopathy with fatal cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -

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

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 31, 2024

- -

Dilated cardiomyopathy 1G

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases allowed determination this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -

Cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

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

Aug 30, 2019

- -

Tibial muscular dystrophy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -

Myopathy, myofibrillar, 9, with early respiratory failure

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -

Hypertrophic cardiomyopathy

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

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

Jul 06, 2017

- -

Cardiovascular phenotype

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 07, 2019

Other strong data supporting benign classification -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.91

BayesDel_addAF

Benign

-0.12

BayesDel_noAF

Uncertain

0.050

CADD

Uncertain

DANN

Uncertain

0.99

Eigen

Pathogenic

0.88

Eigen_PC

Pathogenic

0.86

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.97

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

M_CAP

Benign

0.073

MetaRNN

Benign

0.018

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

MetaSVM

Uncertain

0.015

MutationTaster

Benign

1.0

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

PrimateAI

Uncertain

0.68

PROVEAN

Pathogenic

-5.8

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

REVEL

Pathogenic

0.71

Sift

Uncertain

0.0030

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

Sift4G

Pathogenic

0.0010

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

Polyphen

1.0

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

Vest4

0.53

MVP

0.73

MPC

0.51

ClinPred

0.060

GERP RS

5.9

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