rs200144345

Positions:

chr2-178575096-C-T

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 1P and 5B. PP2BP4_StrongBP6

The NM_001267550.2(TTN):c.71036G>A(p.Arg23679Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000593 in 1,613,266 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 0.00041 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00061 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:15

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 Likely_benign. Variant got -4 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=0.029128432).

BP6

Variant 2-178575096-C-T is Benign according to our data. Variant chr2-178575096-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 192159.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=3, Benign=7, Uncertain_significance=5}. Variant chr2-178575096-C-T is described in Lovd as [Benign]. Variant chr2-178575096-C-T is described in Lovd as [Likely_benign].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.71036G>A	p.Arg23679Lys	missense_variant	326/363	ENST00000589042.5	NP_001254479.2
TTN-AS1	NR_038272.1 linkuse as main transcript	n.2044-7476C>T		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.71036G>A	p.Arg23679Lys	missense_variant	326/363	5	NM_001267550.2	ENSP00000467141	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.417-22500C>T		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.000408

AC:

AN:

152078

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000393

Gnomad ASJ

AF:

0.00259

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000622

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.000574

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.000492

AC:

122

AN:

248070

Hom.:

AF XY:

0.000483

AC XY:

AN XY:

134626

show subpopulations

Gnomad AFR exome

AF:

0.0000647

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00309

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.000687

Gnomad FIN exome

AF:

0.0000465

Gnomad NFE exome

AF:

0.000570

Gnomad OTH exome

AF:

0.000667

GnomAD4 exome

AF:

0.000612

AC:

894

AN:

1461070

Hom.:

Cov.:

AF XY:

0.000640

AC XY:

465

AN XY:

726826

show subpopulations

Gnomad4 AFR exome

AF:

0.0000598

Gnomad4 AMR exome

AF:

0.0000447

Gnomad4 ASJ exome

AF:

0.00287

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000696

Gnomad4 FIN exome

AF:

0.0000750

Gnomad4 NFE exome

AF:

0.000630

Gnomad4 OTH exome

AF:

0.000729

GnomAD4 genome

AF:

0.000407

AC:

AN:

152196

Hom.:

Cov.:

AF XY:

0.000390

AC XY:

AN XY:

74394

show subpopulations

Gnomad4 AFR

AF:

0.0000722

Gnomad4 AMR

AF:

0.000392

Gnomad4 ASJ

AF:

0.00259

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000622

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000574

Gnomad4 OTH

AF:

0.000473

Alfa

AF:

0.000679

Hom.:

Bravo

AF:

0.000340

TwinsUK

AF:

0.000809

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000365

AC:

ExAC

AF:

0.000406

AC:

EpiCase

AF:

0.000764

EpiControl

AF:

0.000534

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5Benign:15

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Benign:8

Benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Oct 24, 2019	proposed classification - variant undergoing re-assessment, contact laboratory -
Benign, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, University Medical Center Utrecht	-	- -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -
Benign, criteria provided, single submitter	clinical testing	Athena Diagnostics	Jun 29, 2020	- -
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	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Mar 12, 2024	Variant summary: TTN c.63332G>A (p.Arg21111Lys) results in a conservative amino acid change in the encoded protein sequence. Two of four in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00059 in 1606300 control chromosomes in the gnomAD database, including 1 homozygote. The observed variant frequency is approximately 1.5-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. To our knowledge, no occurrence of c.63332G>A in individuals affected with Dilated Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 192159). Based on the evidence outlined above, the variant was classified as benign. -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Dec 21, 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	Eurofins Ntd Llc (ga)	Nov 07, 2017	- -

not provided

Uncertain:1Benign:3

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

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). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant 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;C1858763:Dilated cardiomyopathy 1G

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 07, 2017

- -

Dilated cardiomyopathy 1G

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. -

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. -

Cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

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

Oct 30, 2017

- -

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. -

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. -

Cardiovascular phenotype

Benign:1

Benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 10, 2020

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

Uncertain

0.41

BayesDel_addAF

Benign

-0.37

BayesDel_noAF

Benign

-0.33

CADD

Benign

DANN

Benign

0.89

Eigen

Pathogenic

0.87

Eigen_PC

Pathogenic

0.85

FATHMM_MKL

Uncertain

0.95

LIST_S2

Uncertain

0.91

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

M_CAP

Benign

0.015

MetaRNN

Benign

0.029

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

MetaSVM

Benign

-0.44

MutationAssessor

Uncertain

2.5

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

MutationTaster

Benign

1.0

D;D;D;D;D;D

PrimateAI

Uncertain

0.65

PROVEAN

Benign

-2.2

N;N;.;.;N;N;.

REVEL

Benign

0.22

Sift

Benign

0.076

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

Polyphen

1.0

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

Vest4

0.39

MVP

0.33

MPC

0.46

ClinPred

0.11

GERP RS

5.6

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