2-178552365-G-A

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BP4

The NM_001267550.2(TTN):​c.90535C>T​(p.Arg30179Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000326 in 1,593,996 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R30179H) has been classified as Benign.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000033 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

4
6
7

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 5.67

Publications

8 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: Likely_benign. The variant received -1 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.362998).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.90535C>T p.Arg30179Cys missense_variant Exon 335 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.90535C>T p.Arg30179Cys missense_variant Exon 335 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152142
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000724
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000193
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:
0.0000385
AC:
9
AN:
233594
AF XY:
0.0000556
show subpopulations
Gnomad AFR exome
AF:
0.0000653
Gnomad AMR exome
AF:
0.0000305
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000187
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000326
AC:
47
AN:
1441854
Hom.:
0
Cov.:
33
AF XY:
0.0000406
AC XY:
29
AN XY:
714708
show subpopulations
African (AFR)
AF:
0.0000608
AC:
2
AN:
32882
American (AMR)
AF:
0.0000232
AC:
1
AN:
43036
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
24956
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39382
South Asian (SAS)
AF:
0.000364
AC:
30
AN:
82416
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5674
European-Non Finnish (NFE)
AF:
0.0000109
AC:
12
AN:
1101432
Other (OTH)
AF:
0.0000336
AC:
2
AN:
59454
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.493
Heterozygous variant carriers
0
4
9
13
18
22
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:
0.0000329
AC:
5
AN:
152142
Hom.:
0
Cov.:
33
AF XY:
0.0000404
AC XY:
3
AN XY:
74310
show subpopulations
African (AFR)
AF:
0.0000724
AC:
3
AN:
41448
American (AMR)
AF:
0.00
AC:
0
AN:
15252
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5180
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4816
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68038
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.515
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.00
Hom.:
0
Bravo
AF:
0.0000151
ExAC
AF:
0.0000414
AC:
5

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Cardiovascular phenotype Uncertain:1
May 30, 2018
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R21114C variant (also known as c.63340C>T), located in coding exon 162 of the TTN gene, results from a C to T substitution at nucleotide position 63340. The arginine at codon 21114 is replaced by cysteine, an amino acid with highly dissimilar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.19
BayesDel_addAF
Benign
-0.12
T
BayesDel_noAF
Benign
-0.14
CADD
Benign
22
DANN
Benign
0.94
Eigen
Pathogenic
0.76
Eigen_PC
Pathogenic
0.73
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.96
D;D;D;.;D;D;D
M_CAP
Benign
0.040
D
MetaRNN
Benign
0.36
T;T;T;T;T;T;T
MetaSVM
Uncertain
-0.14
T
MutationAssessor
Uncertain
2.7
.;.;.;M;.;.;M
PhyloP100
5.7
PrimateAI
Uncertain
0.68
T
PROVEAN
Pathogenic
-5.5
D;D;.;.;D;D;.
REVEL
Uncertain
0.43
Sift
Uncertain
0.0050
D;D;.;.;D;D;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.47
MutPred
0.57
.;.;.;Loss of MoRF binding (P = 0.0241);.;.;Loss of MoRF binding (P = 0.0241);
MVP
0.73
MPC
0.54
ClinPred
0.29
T
GERP RS
5.8
Mutation Taster
=78/22
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: rs769360937; hg19: chr2-179417092; COSMIC: COSV59949651; COSMIC: COSV59949651; API