chr2-178539109-G-C

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_StrongBP6

The NM_001267550.2(TTN):c.98826C>G(p.Asp32942Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000359 in 1,613,746 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/20 in silico tools predict 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. D32942D) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00020 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000019 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:3

Conservation

PhyloP100: 0.981

Publications

0 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 -5 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.014577538).

BP6

Variant 2-178539109-G-C is Benign according to our data. Variant chr2-178539109-G-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 96323.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.98826C>G	p.Asp32942Glu	missense_variant	Exon 353 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.98826C>G	p.Asp32942Glu	missense_variant	Exon 353 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.000197

AC:

AN:

152106

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000676

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000683

AC:

AN:

248738

AF XY:

0.0000889

show subpopulations

Gnomad AFR exome

AF:

0.000968

Gnomad AMR exome

AF:

0.0000290

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000888

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000192

AC:

AN:

1461522

Hom.:

Cov.:

AF XY:

0.0000206

AC XY:

AN XY:

727046

show subpopulations

African (AFR)

AF:

0.000628

AC:

AN:

33458

American (AMR)

AF:

0.0000671

AC:

AN:

44716

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26128

East Asian (EAS)

AF:

0.00

AC:

AN:

39696

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53400

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.00000180

AC:

AN:

1111736

Other (OTH)

AF:

0.0000331

AC:

AN:

60364

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.468

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:

0.000197

AC:

AN:

152224

Hom.:

Cov.:

AF XY:

0.000242

AC XY:

AN XY:

74412

show subpopulations

African (AFR)

AF:

0.000674

AC:

AN:

41546

American (AMR)

AF:

0.000131

AC:

AN:

15284

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5160

South Asian (SAS)

AF:

0.00

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:

0.00

AC:

AN:

68010

Other (OTH)

AF:

0.00

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.522

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:

0.000216

Hom.:

Bravo

AF:

0.000272

ESP6500AA

AF:

0.000703

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000107

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4Benign:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2Benign:1

Jun 21, 2019

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jul 26, 2013

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

May 07, 2018

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

TTN-related disorder

Uncertain:1

Mar 28, 2024

PreventionGenetics, part of Exact Sciences

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

The TTN c.98826C>G variant is predicted to result in the amino acid substitution p.Asp32942Glu. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.099% of alleles in individuals of African 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

Aug 06, 2016

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not specified

Benign:1

May 03, 2021

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

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: TTN c.91122C>G (p.Asp30374Glu) results in a conservative amino acid change located in the A-band region (cardiodb.org) of the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 6.8e-05 in 248738 control chromosomes, predominantly at a frequency of 0.00097 within the African or African-American subpopulation in the gnomAD database. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 2.5- fold the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Dilated Cardiomyopathy phenotype (0.00039), strongly suggesting that the variant is a benign polymorphism found primarily in populations of African or African-American origin. To our knowledge, no occurrence of c.91122C>G in individuals affected with Dilated Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Both laboratories cited the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as likely benign. -

Cardiovascular phenotype

Benign:1

Oct 11, 2018

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

AlphaMissense

Benign

0.10

BayesDel_addAF

Benign

-0.56

BayesDel_noAF

Benign

-0.64

CADD

Benign

(source)

DANN

Benign

0.78

Eigen

Benign

-0.40

Eigen_PC

Benign

-0.17

FATHMM_MKL

Uncertain

0.76

LIST_S2

Benign

0.72

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

M_CAP

Benign

0.033

MetaRNN

Benign

0.015

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

MetaSVM

Benign

-0.97

MutationAssessor

Benign

0.025

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

PhyloP100

0.98

PrimateAI

Uncertain

0.63

PROVEAN

Benign

-1.8

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

REVEL

Benign

0.11

Sift

Benign

0.86

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

Polyphen

0.0060

.;.;.;B;.;.;B

Vest4

0.10

MutPred

0.47

.;.;.;Gain of ubiquitination at K31302 (P = 0.0817);.;.;Gain of ubiquitination at K31302 (P = 0.0817);

MVP

0.11

MPC

0.080

ClinPred

0.026

GERP RS

4.2

Mutation Taster

=62/38

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