rs185620750

Positions:

chr2-178579324-C-T

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 1P and 4B. PP2BP4_Strong

The NM_001267550.2(TTN):c.67706G>A(p.Arg22569Gln) variant causes a missense change. The variant allele was found at a frequency of 0.000074 in 1,607,914 control chromosomes in the GnomAD database, including 1 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 0.00028 ( 1 hom., cov: 32)

Exomes 𝑓: 0.000052 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6B:1O:1

Conservation

PhyloP100: 4.89

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:

(HGNC:):

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.

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=0.043661565).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.67706G>A	p.Arg22569Gln	missense_variant	320/363	ENST00000589042.5	NP_001254479.2
TTN-AS1	NR_038272.1 linkuse as main transcript	n.2044-3248C>T		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris
TTN	ENST00000589042.5 linkuse as main transcript	c.67706G>A	p.Arg22569Gln	missense_variant	320/363	5	NM_001267550.2	ENSP00000467141	P1
	ENST00000603521.1 linkuse as main transcript	n.535C>T		non_coding_transcript_exon_variant	1/1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.417-18272C>T		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.000283

AC:

AN:

152010

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00262

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000388

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000163

AC:

AN:

246004

Hom.:

AF XY:

0.000142

AC XY:

AN XY:

133534

show subpopulations

Gnomad AFR exome

AF:

0.0000647

Gnomad AMR exome

AF:

0.000962

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000168

Gnomad SAS exome

AF:

0.0000661

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.000167

GnomAD4 exome

AF:

0.0000522

AC:

AN:

1455786

Hom.:

Cov.:

AF XY:

0.0000608

AC XY:

AN XY:

723470

show subpopulations

Gnomad4 AFR exome

AF:

0.0000301

Gnomad4 AMR exome

AF:

0.000832

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000228

Gnomad4 SAS exome

AF:

0.0000233

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000235

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.000283

AC:

AN:

152128

Hom.:

Cov.:

AF XY:

0.000376

AC XY:

AN XY:

74380

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00262

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000389

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000337

Hom.:

Bravo

AF:

0.000234

ExAC

AF:

0.0000662

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6Benign:1Other:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:3Other:1

Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Sep 13, 2022	- -
not provided, no classification provided	clinical testing	GeneDx	Jun 23, 2014	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jan 13, 2017	- -
Uncertain significance, no assertion criteria provided	provider interpretation	Stanford Center for Inherited Cardiovascular Disease, Stanford University	Dec 07, 2016	- -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Feb 06, 2015

The p.Arg20001Gln variant in TTN has not been previously reported in individuals with cardiomyopathy, but has been identified in 6/11478 Latino chromosomes by t he Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; dbSNP rs1 85620750). Computational prediction tools and conservation analysis do not provi de strong support for or against an impact to the protein. In summary, the clini cal significance of the p.Arg20001Gln variant is uncertain. -

TTN-related disorder

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

May 11, 2023

The TTN c.67706G>A variant is predicted to result in the amino acid substitution p.Arg22569Gln. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.096% of alleles in individuals of Latino descent in gnomAD (http://gnomad.broadinstitute.org/variant/2-179444051-C-T). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

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

Oct 24, 2017

- -

Cardiovascular phenotype

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

May 24, 2019

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

0.12

BayesDel_addAF

Benign

-0.36

BayesDel_noAF

Benign

-0.35

CADD

Benign

DANN

Benign

0.96

Eigen

Pathogenic

0.71

Eigen_PC

Pathogenic

0.72

FATHMM_MKL

Uncertain

0.91

LIST_S2

Uncertain

0.96

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

M_CAP

Benign

0.023

MetaRNN

Benign

0.044

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

MetaSVM

Benign

-0.81

MutationAssessor

Uncertain

2.3

.;.;.;M;.;.;M

MutationTaster

Benign

1.0

D;D;D;D;D;D

PrimateAI

Uncertain

0.59

PROVEAN

Uncertain

-2.5

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

REVEL

Benign

0.27

Sift

Benign

0.048

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

Polyphen

1.0

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

Vest4

0.20

MVP

0.19

MPC

0.43

ClinPred

0.075

GERP RS

5.7

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