rs201954720

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_001267550.2(TTN):c.102524G>A(p.Arg34175Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000793 in 1,613,912 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. R34175R) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00011 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000076 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:1

Conservation

PhyloP100: 7.82

Publications

6 publications found

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 was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.19706124).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.102524G>A	p.Arg34175Gln	missense_variant	Exon 358 of 363	ENST00000589042.5	NP_001254479.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 link	c.102524G>A	p.Arg34175Gln	missense_variant	Exon 358 of 363	5	NM_001267550.2	ENSP00000467141.1

Frequencies

GnomAD3 genomes

AF:

0.000112

AC:

AN:

152166

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000415

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000176

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000563

AC:

AN:

248884

AF XY:

0.0000296

show subpopulations

Gnomad AFR exome

AF:

0.000129

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000464

Gnomad NFE exome

AF:

0.0000888

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000759

AC:

111

AN:

1461628

Hom.:

Cov.:

AF XY:

0.0000701

AC XY:

AN XY:

727104

show subpopulations

African (AFR)

AF:

0.0000896

AC:

AN:

33472

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.000176

AC:

AN:

39694

South Asian (SAS)

AF:

0.000116

AC:

AN:

86254

European-Finnish (FIN)

AF:

0.0000375

AC:

AN:

53402

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000791

AC:

AN:

1111814

Other (OTH)

AF:

0.0000166

AC:

AN:

60370

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.479

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.000112

AC:

AN:

152284

Hom.:

Cov.:

AF XY:

0.0000940

AC XY:

AN XY:

74466

show subpopulations

African (AFR)

AF:

0.0000722

AC:

AN:

41568

American (AMR)

AF:

0.00

AC:

AN:

15290

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5182

South Asian (SAS)

AF:

0.000415

AC:

AN:

4820

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10614

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000176

AC:

AN:

68020

Other (OTH)

AF:

0.00

AC:

AN:

2116

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.528

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.000138

Hom.:

Bravo

AF:

0.000121

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000241

AC:

ExAC

AF:

0.0000414

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.000237

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1Benign:1

Sep 13, 2022

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Aug 13, 2019

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not specified

Uncertain:1

Feb 03, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: TTN c.94820G>A (p.Arg31607Gln) results in a conservative amino acid change located in the M-band region of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 5.6e-05 in 248884 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in TTN causing Dilated Cardiomyopathy (5.6e-05 vs 0.00039), allowing no conclusion about variant significance. c.94820G>A has been reported in the literature in at least one individual affected with Dilated Cardiomyopathy without evidence of causality (e.g. Johnson_2023). These report(s) do not provide unequivocal conclusions about association of the variant with Dilated Cardiomyopathy. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 37671549). ClinVar contains an entry for this variant (Variation ID: 203066). Based on the evidence outlined above, the variant was classified as uncertain significance. -

TTN-related disorder

Uncertain:1

May 01, 2024

PreventionGenetics, part of Exact Sciences

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

The TTN c.102524G>A variant is predicted to result in the amino acid substitution p.Arg34175Gln. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.0086% of alleles in individuals of European (Non-Finnish) descent in gnomAD. 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

Apr 17, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Cardiovascular phenotype

Uncertain:1

Jan 21, 2019

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.R25110Q variant (also known as c.75329G>A), located in coding exon 185 of the TTN gene, results from a G to A substitution at nucleotide position 75329. The arginine at codon 25110 is replaced by glutamine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.21

BayesDel_addAF

Benign

-0.16

BayesDel_noAF

Benign

-0.23

CADD

Benign

(source)

DANN

Benign

0.97

Eigen

Uncertain

0.63

Eigen_PC

Uncertain

0.65

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.97

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

M_CAP

Benign

0.030

MetaRNN

Benign

0.20

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

MetaSVM

Benign

-0.38

MutationAssessor

Benign

0.88

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

PhyloP100

7.8

PrimateAI

Uncertain

0.52

PROVEAN

Uncertain

-2.7

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

REVEL

Uncertain

0.34

Sift

Benign

0.072

T;T;.;.;T;T;.

Polyphen

1.0

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

Vest4

0.51

MVP

0.25

MPC

0.50

ClinPred

0.14

GERP RS

5.4

Mutation Taster

=92/8

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over