2-178547469-T-G

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM1BP4BP6

The NM_001267550.2(TTN):c.94157A>C(p.Glu31386Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000616 in 1,460,012 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: not found (cov: 33)

Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:1

Conservation

PhyloP100: 8.02

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: Uncertain_significance. The variant received 0 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 6 uncertain in NM_001267550.2

BP4

Computational evidence support a benign effect (MetaRNN=0.35663283).

BP6

Variant 2-178547469-T-G is Benign according to our data. Variant chr2-178547469-T-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 203000.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.94157A>C	p.Glu31386Ala	missense_variant	Exon 339 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.94157A>C	p.Glu31386Ala	missense_variant	Exon 339 of 363	5	NM_001267550.2	ENSP00000467141.1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000815

AC:

AN:

245476

AF XY:

0.00000751

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000181

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000616

AC:

AN:

1460012

Hom.:

Cov.:

AF XY:

0.00000551

AC XY:

AN XY:

726196

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33456

American (AMR)

AF:

0.00

AC:

AN:

44514

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26098

East Asian (EAS)

AF:

0.00

AC:

AN:

39516

South Asian (SAS)

AF:

0.00

AC:

AN:

86090

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53294

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5760

European-Non Finnish (NFE)

AF:

0.00000810

AC:

AN:

1110968

Other (OTH)

AF:

0.00

AC:

AN:

60316

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.519

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

Cov.:

Alfa

AF:

0.0000936

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.00000828

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Uncertain:1Benign:1

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

Mar 26, 2014

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Missense variants in the TTN gene are considered 'unclassified' if they are not previously reported in the literature and do not have >1% frequency in the population to be considered a polymorphism. Research indicates that truncating mutations in the TTN gene are expected to account for approximately 25% of familial and 18% of sporadic idiopathic DCM; however, truncating variants in the TTN gene have been reported in approximately 3% of reported control alleles. There has been little investigation into non-truncating variants. (Herman D et al. Truncations of titin causing dilated cardiomyopathy. N Eng J Med 366:619-628, 2012) The variant is found in CARDIOMYOPATHY panel(s).

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

Uncertain:1

Sep 05, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.77

BayesDel_addAF

Benign

-0.036

BayesDel_noAF

Benign

-0.23

CADD

Benign

(source)

DANN

Uncertain

0.98

DEOGEN2

Benign

0.0

.;.;.;.;.;.;.

Eigen

Pathogenic

0.80

Eigen_PC

Pathogenic

0.81

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.94

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

M_CAP

Benign

0.035

MetaRNN

Benign

0.36

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

MetaSVM

Benign

-0.45

MutationAssessor

Benign

0.0

.;.;.;M;.;.;M

PhyloP100

8.0

PrimateAI

Uncertain

0.78

PROVEAN

Pathogenic

-4.4

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

REVEL

Uncertain

0.37

Sift

Uncertain

0.0070

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

Sift4G

Pathogenic

0.0

.;.;.;.;.;.;.

Vest4

0.48

ClinPred

0.36

GERP RS

6.0

Mutation Taster

=58/42

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

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over