2-178634818-C-T

Variant names:

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_StrongBP6BS1

The NM_001267550.2(TTN):c.42056G>A(p.Arg14019His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000128 in 1,611,684 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R14019C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00013 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 7.48

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: Benign. The variant received -9 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.01751095).

BP6

Variant 2-178634818-C-T is Benign according to our data. Variant chr2-178634818-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 179051.

BS1

Variant frequency is greater than expected in population sas. GnomAdExome4 allele frequency = 0.000135 (197/1459532) while in subpopulation SAS AF = 0.00208 (178/85666). AF 95% confidence interval is 0.00183. There are 1 homozygotes in GnomAdExome4. There are 145 alleles in the male GnomAdExome4 subpopulation. Median coverage is 32. This position passed quality control check.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.42056G>A	p.Arg14019His	missense_variant	Exon 229 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.42056G>A	p.Arg14019His	missense_variant	Exon 229 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.0000658

AC:

AN:

152034

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00166

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000223

AC:

AN:

246758

AF XY:

0.000291

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:

0.0000357

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000135

AC:

197

AN:

1459532

Hom.:

Cov.:

AF XY:

0.000200

AC XY:

145

AN XY:

725942

show subpopulations

African (AFR)

AF:

0.0000900

AC:

AN:

33320

American (AMR)

AF:

0.00

AC:

AN:

44372

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26096

East Asian (EAS)

AF:

0.00

AC:

AN:

39612

South Asian (SAS)

AF:

0.00208

AC:

178

AN:

85666

European-Finnish (FIN)

AF:

0.0000187

AC:

AN:

53358

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5754

European-Non Finnish (NFE)

AF:

0.00000810

AC:

AN:

1111080

Other (OTH)

AF:

0.0000995

AC:

AN:

60274

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

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

<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:

0.0000592

AC:

AN:

152152

Hom.:

Cov.:

AF XY:

0.0000672

AC XY:

AN XY:

74368

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41532

American (AMR)

AF:

0.00

AC:

AN:

15272

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5144

South Asian (SAS)

AF:

0.00145

AC:

AN:

4816

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10614

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

67986

Other (OTH)

AF:

0.00

AC:

AN:

2112

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

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:

0.00

Hom.:

Bravo

AF:

0.0000189

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000122

AC:

ExAC

AF:

0.000290

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1Benign:1

Jul 17, 2018

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Oct 01, 2019

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not specified

Uncertain:1

Mar 19, 2014

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The Arg11451His variant in TTN has not been previously reported in individuals w ith cardiomyopathy, but has been identified in 1/8184 European American chromoso mes by the NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS/). C omputational prediction tools and conservation analysis suggest that this varian t may impact the protein, though this information is not predictive enough to de termine pathogenicity. Additional information is needed to fully assess the clin ical significance of this variant. -

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

Benign:1

Nov 04, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.34

BayesDel_addAF

Benign

-0.35

BayesDel_noAF

Benign

-0.30

CADD

Uncertain

(source)

DANN

Benign

0.94

Eigen

Pathogenic

0.74

Eigen_PC

Pathogenic

0.80

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.94

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

M_CAP

Benign

0.019

MetaRNN

Benign

0.018

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

MetaSVM

Benign

-0.87

MutationAssessor

Benign

1.1

.;.;.;L;.;.;L

PhyloP100

7.5

PrimateAI

Uncertain

0.78

PROVEAN

Uncertain

-3.7

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

REVEL

Uncertain

0.41

Sift

Benign

0.077

T;D;.;.;D;D;.

Polyphen

1.0

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

Vest4

0.28

MVP

0.22

MPC

0.51

ClinPred

0.19

GERP RS

6.2

Mutation Taster

=70/30

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