chr2-178569059-A-G

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_StrongBP6BP7

The NM_001267550.2(TTN):c.77073T>C(p.Asp25691Asp) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000093 in 1,613,212 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).

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000096 ( 0 hom. )

Consequence

TTN
NM_001267550.2 synonymous

Scores

Clinical Significance

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

Conservation

PhyloP100: 0.849

Publications

2 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 -6 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.54).

BP6

Variant 2-178569059-A-G is Benign according to our data. Variant chr2-178569059-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 47353.

BP7

Synonymous conserved (PhyloP=0.849 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.77073T>C	p.Asp25691Asp	synonymous_variant	Exon 326 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.77073T>C	p.Asp25691Asp	synonymous_variant	Exon 326 of 363	5	NM_001267550.2	ENSP00000467141.1

Frequencies

GnomAD3 genomes

AF:

0.0000658

AC:

AN:

152076

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

Gnomad ASJ

AF:

0.00144

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000201

AC:

AN:

248334

AF XY:

0.000193

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000319

Gnomad ASJ exome

AF:

0.00339

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000356

Gnomad OTH exome

AF:

0.000166

GnomAD4 exome

AF:

0.0000958

AC:

140

AN:

1461136

Hom.:

Cov.:

AF XY:

0.0000936

AC XY:

AN XY:

726852

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33440

American (AMR)

AF:

0.000268

AC:

AN:

44704

Ashkenazi Jewish (ASJ)

AF:

0.00326

AC:

AN:

26108

East Asian (EAS)

AF:

0.00

AC:

AN:

39652

South Asian (SAS)

AF:

0.00

AC:

AN:

86204

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53350

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5758

European-Non Finnish (NFE)

AF:

0.0000243

AC:

AN:

1111576

Other (OTH)

AF:

0.000265

AC:

AN:

60344

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.497

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:

0.0000658

AC:

AN:

152076

Hom.:

Cov.:

AF XY:

0.000108

AC XY:

AN XY:

74274

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41432

American (AMR)

AF:

0.000131

AC:

AN:

15244

Ashkenazi Jewish (ASJ)

AF:

0.00144

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5168

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10626

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

67988

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.535

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:

0.000310

Hom.:

Bravo

AF:

0.000140

EpiCase

AF:

0.00

EpiControl

AF:

0.0000594

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6Benign:6

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1Benign:3

Feb 06, 2018

Athena Diagnostics

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Mar 03, 2016

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Sep 30, 2020

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 01, 2024

CeGaT Center for Human Genetics Tuebingen

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

TTN: BP4, BP7 -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Uncertain:1

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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. -

Dilated cardiomyopathy 1G

Uncertain:1

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Early-onset myopathy with fatal cardiomyopathy

Uncertain:1

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Tibial muscular dystrophy

Uncertain:1

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Myopathy, myofibrillar, 9, with early respiratory failure

Uncertain:1

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

not specified

Benign:1

Mar 22, 2012

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Asp23123Asp in exon 275 of TTN: This variant is not expected to have clinical si gnificance because it does not alter an amino acid residue and is not located wi thin the splice consensus sequence. This variant has been identified in 0.01% (1 /6732) of European American chromosomes from a broad population by the NHLBI Exo me Sequencing Project (http://evs.gs.washington.edu/EVS/) Asp23123Asp in exo n 275 of TTN (allele frequency = 0.01%, 1/6732) ** -

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

Benign:1

Jan 27, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Cardiovascular phenotype

Benign:1

Oct 19, 2016

Ambry Genetics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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

BayesDel_noAF

Benign

-0.54

CADD

Benign

0.34

(source)

DANN

Benign

0.76

PhyloP100

0.85

Mutation Taster

=90/10

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