chr2-178783725-C-T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_001267550.2(TTN):​c.2836G>A​(p.Val946Ile) variant causes a missense change. The variant allele was found at a frequency of 0.0000304 in 1,613,092 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. V946V) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000033 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

7
10

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 3.63

Publications

3 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 Gene-Disease associations (from GenCC):
  • dilated cardiomyopathy
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • dilated cardiomyopathy 1G
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
  • early-onset myopathy with fatal cardiomyopathy
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, G2P
  • TTN-related myopathy
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • myopathy, myofibrillar, 9, with early respiratory failure
    Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, ClinGen, Ambry Genetics
  • tibial muscular dystrophy
    Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen, Orphanet
  • autosomal recessive limb-girdle muscular dystrophy type 2J
    Inheritance: AR Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Orphanet
  • hypertrophic cardiomyopathy 9
    Inheritance: AD Classification: MODERATE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia
  • familial isolated dilated cardiomyopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • autosomal recessive centronuclear myopathy
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • childhood-onset progressive contractures-limb-girdle weakness-muscle dystrophy syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • arrhythmogenic right ventricular cardiomyopathy
    Inheritance: AD Classification: LIMITED Submitted by: ClinGen
  • congenital myopathy
    Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
  • hereditary skeletal muscle disorder
    Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
  • hypertrophic cardiomyopathy
    Inheritance: AD Classification: LIMITED Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.21781132).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.2836G>A p.Val946Ile missense_variant Exon 17 of 363 ENST00000589042.5 NP_001254479.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.2836G>A p.Val946Ile missense_variant Exon 17 of 363 5 NM_001267550.2 ENSP00000467141.1

Frequencies

GnomAD3 genomes
AF:
0.00000659
AC:
1
AN:
151788
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
251278
AF XY:
0.0000147
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:
0.0000352
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000328
AC:
48
AN:
1461304
Hom.:
0
Cov.:
30
AF XY:
0.0000344
AC XY:
25
AN XY:
726984
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33450
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26118
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39646
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86246
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53392
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.0000432
AC:
48
AN:
1111608
Other (OTH)
AF:
0.00
AC:
0
AN:
60358
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.456
Heterozygous variant carriers
0
3
6
9
12
15
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
AF:
0.00000659
AC:
1
AN:
151788
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74082
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41282
American (AMR)
AF:
0.00
AC:
0
AN:
15238
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4782
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10548
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67986
Other (OTH)
AF:
0.00
AC:
0
AN:
2080
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.000135
Hom.:
0
Bravo
AF:
0.0000113
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000259
AC:
1
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Jan 31, 2016
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiomyopathy Uncertain:1
May 16, 2023
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Nov 16, 2017
Eurofins Ntd Llc (ga)
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
Benign
0.093
BayesDel_addAF
Benign
-0.17
T
BayesDel_noAF
Benign
-0.38
CADD
Benign
22
DANN
Uncertain
0.98
Eigen
Uncertain
0.20
Eigen_PC
Uncertain
0.37
FATHMM_MKL
Uncertain
0.91
D
LIST_S2
Uncertain
0.89
D;D;D;.;D;D;D;D
M_CAP
Uncertain
0.17
D
MetaRNN
Benign
0.22
T;T;T;T;T;T;T;T
MetaSVM
Benign
-0.70
T
PhyloP100
3.6
PrimateAI
Uncertain
0.62
T
PROVEAN
Benign
-0.44
N;N;.;.;N;N;.;N
REVEL
Benign
0.18
Sift
Benign
0.61
T;T;.;.;T;T;.;T
Sift4G
Benign
0.082
.;.;.;.;.;.;.;T
Polyphen
0.37, 0.95
.;.;.;B;.;.;B;P
Vest4
0.23
MVP
0.49
MPC
0.092
ClinPred
0.24
T
GERP RS
5.9
Mutation Taster
=79/21
polymorphism

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

Other links and lift over

dbSNP: rs752246051; hg19: chr2-179648452; API