2-178642293-C-T

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_StrongBP6BS2

The NM_001267550.2(TTN):​c.40502G>A​(p.Arg13501His) variant causes a missense change. The variant allele was found at a frequency of 0.000128 in 1,593,852 control chromosomes in the GnomAD database, including 4 homozygotes. In-silico tool predicts a benign outcome for this variant. 13/20 in silico tools predict 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. R13501C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00011 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00013 ( 4 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

6
12

Clinical Significance

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

Conservation

PhyloP100: 3.64

Publications

2 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-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]

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=0.015265077).
BP6
Variant 2-178642293-C-T is Benign according to our data. Variant chr2-178642293-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 166076.
BS2
High Homozygotes in GnomAdExome4 at 4 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.40502G>A p.Arg13501His missense_variant Exon 219 of 363 ENST00000589042.5 NP_001254479.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.40502G>A p.Arg13501His missense_variant Exon 219 of 363 5 NM_001267550.2 ENSP00000467141.1

Frequencies

GnomAD3 genomes
AF:
0.000105
AC:
16
AN:
151726
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000967
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000659
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00125
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000589
Gnomad OTH
AF:
0.000480
GnomAD2 exomes
AF:
0.000176
AC:
39
AN:
221378
AF XY:
0.000243
show subpopulations
Gnomad AFR exome
AF:
0.000148
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:
0.0000102
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000130
AC:
188
AN:
1442008
Hom.:
4
Cov.:
30
AF XY:
0.000183
AC XY:
131
AN XY:
715610
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33072
American (AMR)
AF:
0.00
AC:
0
AN:
42386
Ashkenazi Jewish (ASJ)
AF:
0.0000390
AC:
1
AN:
25654
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39002
South Asian (SAS)
AF:
0.00175
AC:
145
AN:
82726
European-Finnish (FIN)
AF:
0.0000191
AC:
1
AN:
52452
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5716
European-Non Finnish (NFE)
AF:
0.0000309
AC:
34
AN:
1101462
Other (OTH)
AF:
0.000118
AC:
7
AN:
59538
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.459
Heterozygous variant carriers
0
10
20
29
39
49
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
4
8
12
16
20
<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:
0.000105
AC:
16
AN:
151844
Hom.:
0
Cov.:
32
AF XY:
0.000148
AC XY:
11
AN XY:
74196
show subpopulations
African (AFR)
AF:
0.0000964
AC:
4
AN:
41494
American (AMR)
AF:
0.0000658
AC:
1
AN:
15194
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5144
South Asian (SAS)
AF:
0.00125
AC:
6
AN:
4806
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10580
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000590
AC:
4
AN:
67848
Other (OTH)
AF:
0.000475
AC:
1
AN:
2104
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.497
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000328
Hom.:
0
Bravo
AF:
0.0000529
ExAC
AF:
0.000233
AC:
28
Asia WGS
AF:
0.000867
AC:
3
AN:
3476

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:3Benign:4
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2Benign:1
Jun 12, 2019
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jul 14, 2016
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Aug 07, 2023
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1
Jul 01, 2014
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The Arg10933His variant in TTN has not been previously reported in individuals w ith cardiomyopathy or in large population studies. Computational prediction tool s and conservation analysis do not provide strong support for or against an impa ct to the protein. In summary, the clinical significance of the Arg10933His vari ant is uncertain. -

TTN-related disorder Benign:1
Jun 06, 2024
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely 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 06, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Benign:1
Mar 28, 2020
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
0.33
BayesDel_addAF
Benign
-0.32
T
BayesDel_noAF
Benign
-0.27
CADD
Benign
23
DANN
Uncertain
1.0
DEOGEN2
Benign
0.083
.;.;.;.;.;.;.;T
Eigen
Benign
-0.028
Eigen_PC
Benign
0.13
FATHMM_MKL
Uncertain
0.90
D
LIST_S2
Benign
0.84
T;T;T;.;T;T;T;D
M_CAP
Benign
0.079
D
MetaRNN
Benign
0.015
T;T;T;T;T;T;T;T
MetaSVM
Benign
-0.56
T
MutationAssessor
Uncertain
2.3
.;.;.;M;.;.;M;.
PhyloP100
3.6
PrimateAI
Uncertain
0.65
T
PROVEAN
Uncertain
-2.8
D;N;.;.;N;N;.;N
REVEL
Benign
0.10
Sift
Uncertain
0.0050
D;D;.;.;D;D;.;T
Polyphen
0.014
.;.;.;B;.;.;B;.
Vest4
0.37
MVP
0.22
MPC
0.11
ClinPred
0.11
T
GERP RS
4.7
Mutation Taster
=79/21
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs571348685; hg19: chr2-179507020; COSMIC: COSV100637106; COSMIC: COSV100637106; API