chr2-178684062-C-G

Variant names:

Variant summary

Our verdict is Benign. The variant received -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_001267550.2(TTN):c.32743G>C(p.Ala10915Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000542 in 1,611,914 control chromosomes in the GnomAD database, including 5 homozygotes. In-silico tool predicts a benign outcome for this variant. 15/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0029 ( 2 hom., cov: 31)

Exomes 𝑓: 0.00030 ( 3 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:18

Conservation

PhyloP100: 0.453

Publications

5 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:

LOC124906100 (HGNC:):

LOC124906100 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -20 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.0046764314).

BP6

Variant 2-178684062-C-G is Benign according to our data. Variant chr2-178684062-C-G is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 46877.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BS1

Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00291 (440/151288) while in subpopulation AFR AF = 0.0102 (420/41260). AF 95% confidence interval is 0.00938. There are 2 homozygotes in GnomAd4. There are 196 alleles in the male GnomAd4 subpopulation. Median coverage is 31. This position passed quality control check.

BS2

High Homozygotes in GnomAd4 at 2 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.32743G>C	p.Ala10915Pro	missense_variant	Exon 133 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.32743G>C	p.Ala10915Pro	missense_variant	Exon 133 of 363	5	NM_001267550.2	ENSP00000467141.1

Frequencies

GnomAD3 genomes

AF:

0.00292

AC:

441

AN:

151176

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0102

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000859

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000208

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000442

Gnomad OTH

AF:

0.00193

GnomAD2 exomes

AF:

0.000760

AC:

189

AN:

248774

AF XY:

0.000548

show subpopulations

Gnomad AFR exome

AF:

0.0107

Gnomad AMR exome

AF:

0.000639

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000887

Gnomad OTH exome

AF:

0.000166

GnomAD4 exome

AF:

0.000296

AC:

433

AN:

1460626

Hom.:

Cov.:

AF XY:

0.000252

AC XY:

183

AN XY:

726562

show subpopulations

African (AFR)

AF:

0.0109

AC:

365

AN:

33436

American (AMR)

AF:

0.000604

AC:

AN:

44684

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26100

East Asian (EAS)

AF:

0.00

AC:

AN:

39654

South Asian (SAS)

AF:

0.0000232

AC:

AN:

86052

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53340

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.00000450

AC:

AN:

1111258

Other (OTH)

AF:

0.000547

AC:

AN:

60338

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.439

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome 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

GnomAD4 genome

AF:

0.00291

AC:

440

AN:

151288

Hom.:

Cov.:

AF XY:

0.00265

AC XY:

196

AN XY:

73866

show subpopulations

African (AFR)

AF:

0.0102

AC:

420

AN:

41260

American (AMR)

AF:

0.000858

AC:

AN:

15152

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3460

East Asian (EAS)

AF:

0.00

AC:

AN:

5138

South Asian (SAS)

AF:

0.00

AC:

AN:

4800

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10392

Middle Eastern (MID)

AF:

0.00

AC:

AN:

292

European-Non Finnish (NFE)

AF:

0.0000443

AC:

AN:

67794

Other (OTH)

AF:

0.00191

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.507

Heterozygous variant carriers

100

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:

0.000526

Hom.:

Bravo

AF:

0.00362

ESP6500AA

AF:

0.00829

AC:

ESP6500EA

AF:

0.000123

AC:

ExAC

AF:

0.000911

AC:

110

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:18

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:7

Clinical Genetics, Academic Medical Center

Significance:Benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Aug 24, 2015

Genetic Services Laboratory, University of Chicago

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

May 05, 2017

Athena Diagnostics

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

May 06, 2015

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

p.Ala9671Pro in exon 130 of TTN: This variant is not expected to have clinical s ignificance because it has been identified in 1.0% (98/9782) of African chromoso mes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; d bSNP rs72650032). -

Dec 25, 2016

Eurofins Ntd Llc (ga)

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Apr 09, 2025

Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Aug 08, 2021

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

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not provided

Benign:4

Nov 27, 2020

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

May 01, 2025

CeGaT Center for Human Genetics Tuebingen

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

TTN: BP4, BS1 -

Oct 10, 2023

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Benign:1

Sep 10, 2021

Genome-Nilou Lab

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

TTN-related disorder

Benign:1

Jan 11, 2021

PreventionGenetics, part of Exact Sciences

Significance:Benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

This variant is classified as benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

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

Benign:1

Jan 30, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Early-onset myopathy with fatal cardiomyopathy

Benign:1

Sep 10, 2021

Genome-Nilou Lab

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Tibial muscular dystrophy

Benign:1

Sep 10, 2021

Genome-Nilou Lab

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Myopathy, myofibrillar, 9, with early respiratory failure

Benign:1

Sep 10, 2021

Genome-Nilou Lab

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Cardiovascular phenotype

Benign:1

Sep 18, 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

AlphaMissense

Benign

0.12

BayesDel_addAF

Benign

-0.45

BayesDel_noAF

Benign

-0.41

CADD

Benign

(source)

DANN

Benign

0.90

Eigen

Benign

-0.65

Eigen_PC

Benign

-0.45

FATHMM_MKL

Benign

0.34

LIST_S2

Benign

0.56

T;T;.;T

MetaRNN

Benign

0.0047

T;T;T;T

MetaSVM

Benign

-1.1

PhyloP100

0.45

PrimateAI

Benign

0.31

PROVEAN

Benign

-1.2

N;.;.;.

REVEL

Benign

0.083

Sift

Benign

0.093

T;.;.;.

Polyphen

0.0

.;.;B;B

Vest4

0.28

MVP

0.18

MPC

0.11

ClinPred

0.012

GERP RS

2.8

Mutation Taster

=95/5

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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