rs199643269

Positions:

chr2-178582197-G-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 1P and 3B. PP2BP4_ModerateBP6

The NM_001267550.2(TTN):c.66172C>T(p.Arg22058Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000842 in 1,603,578 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 0.00039 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000052 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:2

Conservation

PhyloP100: 6.58

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 Likely_benign. Variant got -2 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=0.0972265).

BP6

Variant 2-178582197-G-A is Benign according to our data. Variant chr2-178582197-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 229491.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=3}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.66172C>T	p.Arg22058Cys	missense_variant	315/363	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.66172C>T	p.Arg22058Cys	missense_variant	315/363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.000388

AC:

AN:

151974

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00130

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000657

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:

0.0000441

Gnomad OTH

AF:

0.000479

GnomAD3 exomes

AF:

0.000109

AC:

AN:

238176

Hom.:

AF XY:

0.0000851

AC XY:

AN XY:

129206

show subpopulations

Gnomad AFR exome

AF:

0.00106

Gnomad AMR exome

AF:

0.0000624

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000717

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000458

Gnomad OTH exome

AF:

0.000172

GnomAD4 exome

AF:

0.0000524

AC:

AN:

1451486

Hom.:

Cov.:

AF XY:

0.0000430

AC XY:

AN XY:

721748

show subpopulations

Gnomad4 AFR exome

AF:

0.00104

Gnomad4 AMR exome

AF:

0.0000955

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000598

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000252

Gnomad4 OTH exome

AF:

0.0000834

GnomAD4 genome

AF:

0.000388

AC:

AN:

152092

Hom.:

Cov.:

AF XY:

0.000309

AC XY:

AN XY:

74336

show subpopulations

Gnomad4 AFR

AF:

0.00130

Gnomad4 AMR

AF:

0.0000656

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.000474

Alfa

AF:

0.0000801

Hom.:

Bravo

AF:

0.000495

ESP6500AA

AF:

0.00135

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000108

AC:

Asia WGS

AF:

0.000577

AC:

AN:

3478

EpiCase

AF:

0.00

EpiControl

AF:

0.000178

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Apr 06, 2017	- -
Uncertain significance, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Uncertain significance, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -

not specified

Uncertain:1Benign:1

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Mar 15, 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Jun 28, 2017	The p.Arg19490Cys variant in TTN has been reported by our laboratory in 1 indivi dual with DCM, has been identified in 0.09% (20/23668) of African chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org/; dbS NP rs199643269), and has been reported in ClinVar (Variation ID: 229491). While truncating variants in TTN are strongly associated with DCM (Herman 2012), the r ole of missense variants and in-frame deletions/insertions has yet to be elucida ted. Computational prediction tools and conservation analysis do not provide str ong support for or against an impact to the protein. In summary, the clinical si gnificance of the p.Arg19490Cys variant is uncertain. -

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

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 12, 2017

- -

Cardiovascular phenotype

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 12, 2020

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

Benign

0.11

BayesDel_addAF

Benign

-0.34

BayesDel_noAF

Benign

-0.32

CADD

Uncertain

DANN

Benign

0.92

Eigen

Pathogenic

0.69

Eigen_PC

Pathogenic

0.74

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.96

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

M_CAP

Benign

0.020

MetaRNN

Benign

0.097

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

MetaSVM

Benign

-0.68

MutationAssessor

Benign

0.97

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

PrimateAI

Benign

0.42

PROVEAN

Pathogenic

-4.4

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

REVEL

Benign

0.28

Sift

Benign

0.089

T;D;.;.;D;D;.

Polyphen

1.0

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

Vest4

0.35

MVP

0.48

MPC

0.31

ClinPred

0.083

GERP RS

5.7

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