2-178563557-C-T

Variant names:

Variant summary

Our verdict is Benign. The variant received -19 ACMG points: 0P and 19B.

-19

BP4_ModerateBP6_Very_StrongBP7BS1BS2

The NM_001267550.2(TTN):c.82575G>A(p.Thr27525Thr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00171 in 1,613,744 control chromosomes in the GnomAD database, including 31 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0090 ( 17 hom., cov: 33)

Exomes 𝑓: 0.00095 ( 14 hom. )

Consequence

TTN
NM_001267550.2 synonymous

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:21

Conservation

PhyloP100: 0.838

Publications

4 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: Benign. The variant received -19 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.39).

BP6

Variant 2-178563557-C-T is Benign according to our data. Variant chr2-178563557-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 47415.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BP7

Synonymous conserved (PhyloP=0.838 with no splicing effect.

BS1

Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00896 (1364/152208) while in subpopulation AFR AF = 0.0305 (1265/41530). AF 95% confidence interval is 0.0291. There are 17 homozygotes in GnomAd4. There are 630 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.

BS2

High Homozygotes in GnomAd4 at 17 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.82575G>A	p.Thr27525Thr	synonymous_variant	Exon 326 of 363	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 link	c.82575G>A	p.Thr27525Thr	synonymous_variant	Exon 326 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.00893

AC:

1358

AN:

152090

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0304

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00426

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.000830

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000221

Gnomad OTH

AF:

0.00669

GnomAD2 exomes

AF:

0.00229

AC:

569

AN:

248878

AF XY:

0.00164

show subpopulations

Gnomad AFR exome

AF:

0.0298

Gnomad AMR exome

AF:

0.00185

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000557

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000186

Gnomad OTH exome

AF:

0.00116

GnomAD4 exome

AF:

0.000954

AC:

1394

AN:

1461536

Hom.:

Cov.:

AF XY:

0.000835

AC XY:

607

AN XY:

727060

show subpopulations

African (AFR)

AF:

0.0303

AC:

1015

AN:

33464

American (AMR)

AF:

0.00212

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.0000765

AC:

AN:

26130

East Asian (EAS)

AF:

0.0000504

AC:

AN:

39682

South Asian (SAS)

AF:

0.000394

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.0000187

AC:

AN:

53400

Middle Eastern (MID)

AF:

0.00208

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.0000881

AC:

AN:

1111748

Other (OTH)

AF:

0.00224

AC:

135

AN:

60368

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.474

Heterozygous variant carriers

105

210

316

421

526

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

108

144

180

<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:

0.00896

AC:

1364

AN:

152208

Hom.:

Cov.:

AF XY:

0.00847

AC XY:

630

AN XY:

74408

show subpopulations

African (AFR)

AF:

0.0305

AC:

1265

AN:

41530

American (AMR)

AF:

0.00425

AC:

AN:

15288

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.000194

AC:

AN:

5162

South Asian (SAS)

AF:

0.000831

AC:

AN:

4816

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10616

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000221

AC:

AN:

68006

Other (OTH)

AF:

0.00662

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.502

Heterozygous variant carriers

136

204

272

340

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Genome Hom

Variant carriers

100

<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:

0.00486

Hom.:

Bravo

AF:

0.0103

Asia WGS

AF:

0.00289

AC:

AN:

3476

EpiCase

AF:

0.000109

EpiControl

AF:

0.000237

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:21

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:7

Mar 07, 2014

GeneDx

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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. -

Aug 19, 2019

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

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+

Significance:Benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Jul 18, 2012

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Thr24957Thr in Exon 275 of TTN: This variant is not expected to have clinical si gnificance because it does not alter an amino acid residue, is not located withi n the splice consensus sequence and has been identified in 2.6% (105/3996) of Af rican American chromosomes from a broad population by the NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS; dbSNP rs11896779). -

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance:Benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Clinical Genetics, Academic Medical Center

Significance:Benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Apr 09, 2025

Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Benign:2

Sep 10, 2021

Genome-Nilou Lab

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Early-onset myopathy with fatal cardiomyopathy

Benign:2

Sep 10, 2021

Genome-Nilou Lab

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

not provided

Benign:2

Nov 29, 2023

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Breakthrough Genomics, Breakthrough Genomics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:not provided

- -

Tibial muscular dystrophy

Benign:2

Sep 10, 2021

Genome-Nilou Lab

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Myopathy, myofibrillar, 9, with early respiratory failure

Benign:2

Sep 10, 2021

Genome-Nilou Lab

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

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

Benign:1

Feb 03, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Dilated cardiomyopathy 1G

Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Cardiomyopathy

Benign:1

Jul 25, 2016

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

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Cardiovascular phenotype

Benign:1

Apr 16, 2013

Ambry Genetics

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This alteration is classified as benign based on a combination of the following: 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

-0.39

CADD

Benign

0.24

(source)

DANN

Benign

0.86

PhyloP100

0.84

Mutation Taster

=81/19

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