2-178723286-C-T

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_001267550.2(TTN):​c.21721G>A​(p.Val7241Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000347 in 1,613,392 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00019 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

16

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:1

Conservation

PhyloP100: 1.97

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-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 -4 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.03912151).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.21721G>A p.Val7241Ile missense_variant Exon 75 of 363 ENST00000589042.5 NP_001254479.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.21721G>A p.Val7241Ile missense_variant Exon 75 of 363 5 NM_001267550.2 ENSP00000467141.1

Frequencies

GnomAD3 genomes
AF:
0.000191
AC:
29
AN:
152120
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000676
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000405
AC:
10
AN:
246894
AF XY:
0.0000224
show subpopulations
Gnomad AFR exome
AF:
0.000519
Gnomad AMR exome
AF:
0.0000581
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000185
AC:
27
AN:
1461154
Hom.:
0
Cov.:
33
AF XY:
0.0000193
AC XY:
14
AN XY:
726838
show subpopulations
African (AFR)
AF:
0.000658
AC:
22
AN:
33442
American (AMR)
AF:
0.0000448
AC:
2
AN:
44690
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26114
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39684
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86202
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53320
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
9.00e-7
AC:
1
AN:
1111600
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60340
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.482
Heterozygous variant carriers
0
2
4
6
8
10
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:
0.000190
AC:
29
AN:
152238
Hom.:
0
Cov.:
33
AF XY:
0.000175
AC XY:
13
AN XY:
74434
show subpopulations
African (AFR)
AF:
0.000674
AC:
28
AN:
41568
American (AMR)
AF:
0.0000655
AC:
1
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5174
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67996
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.485
Heterozygous variant carriers
0
2
3
5
6
8
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:
0.000152
Hom.:
0
Bravo
AF:
0.000166
ESP6500AA
AF:
0.000267
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000497
AC:
6

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:4Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2Benign:1
Aug 06, 2019
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Oct 25, 2016
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 12, 2021
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1
May 22, 2017
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant classified as Uncertain Significance - Favor Benign. The p.Val5997Ile va riant in TTN has not been previously reported in individuals with cardiomyopathy , but has been identified in 0.06% (15/23956) of African chromosomes by the geno me Aggregation Database (gnomAD, http://gnomad.broadinstitute.org/; dbSNP rs3678 54582). Computational prediction tools and conservation analysis suggest that th e p.Val5997Ile variant may not impact the protein, though this information is no t predictive enough to rule out pathogenicity. In summary, while the clinical si gnificance of the p.Val5997Ile variant is uncertain, these data suggest that it is more likely to be benign. -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Aug 23, 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
Benign
0.081
BayesDel_addAF
Benign
-0.36
T
BayesDel_noAF
Benign
-0.38
CADD
Benign
18
DANN
Benign
0.80
Eigen
Benign
-0.65
Eigen_PC
Benign
-0.58
FATHMM_MKL
Benign
0.52
D
LIST_S2
Benign
0.67
T;T;.;T
M_CAP
Benign
0.032
D
MetaRNN
Benign
0.039
T;T;T;T
MetaSVM
Benign
-0.77
T
PhyloP100
2.0
PrimateAI
Benign
0.36
T
PROVEAN
Benign
-0.68
N;.;.;.
REVEL
Benign
0.13
Sift
Benign
0.33
T;.;.;.
Polyphen
0.0030
.;.;B;B
Vest4
0.22
MVP
0.17
MPC
0.071
ClinPred
0.018
T
GERP RS
2.0
Mutation Taster
=94/6
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.030
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: rs367854582; hg19: chr2-179588013; API