2-178567060-C-T

Variant summary

Our verdict is Benign. The variant received -12 ACMG points: 0P and 12B. BP4_StrongBP6_Very_Strong

The NM_001267550.2(TTN):​c.79072G>A​(p.Val26358Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000186 in 1,613,442 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.000085 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

1
16

Clinical Significance

Likely benign criteria provided, multiple submitters, no conflicts B:3

Conservation

PhyloP100: 2.30

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: Benign. The variant received -12 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.024711609).
BP6
Variant 2-178567060-C-T is Benign according to our data. Variant chr2-178567060-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 228145.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.79072G>A p.Val26358Ile missense_variant Exon 326 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.79072G>A p.Val26358Ile missense_variant Exon 326 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.0000855
AC:
13
AN:
152070
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000314
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000282
AC:
7
AN:
248458
AF XY:
0.0000223
show subpopulations
Gnomad AFR exome
AF:
0.000129
Gnomad AMR exome
AF:
0.000145
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:
0.0000116
AC:
17
AN:
1461372
Hom.:
0
Cov.:
37
AF XY:
0.0000110
AC XY:
8
AN XY:
726982
show subpopulations
African (AFR)
AF:
0.000269
AC:
9
AN:
33446
American (AMR)
AF:
0.000134
AC:
6
AN:
44714
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26126
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39688
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53400
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111634
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60346
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.469
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

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:
0.0000855
AC:
13
AN:
152070
Hom.:
0
Cov.:
33
AF XY:
0.0000943
AC XY:
7
AN XY:
74266
show subpopulations
African (AFR)
AF:
0.000314
AC:
13
AN:
41426
American (AMR)
AF:
0.00
AC:
0
AN:
15248
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5174
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67988
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.0000660
Hom.:
0
Bravo
AF:
0.000106
ExAC
AF:
0.0000248
AC:
3

ClinVar

Significance: Likely benign
Submissions summary: Benign:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Benign:2
Dec 22, 2023
Revvity Omics, Revvity
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Nov 14, 2019
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Benign:1
Oct 22, 2015
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

p.Val23790Ile in exon 275 of TTN: This variant is not expected to have clinical significance due to a lack of conservation across species, including mammals. Of note, >10 mammals have an isoleucine (Ile) residue at this position despite hig h nearby amino acid sequence conservation. In addition, computational prediction tools do not suggest a high likelihood of impact to the protein. This variant h as been identified in 2/11560 of Latino chromosomes and 1/9796 African chromosom es by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.055
BayesDel_addAF
Benign
-0.40
T
BayesDel_noAF
Benign
-0.58
CADD
Benign
12
DANN
Benign
0.70
Eigen
Benign
-0.83
Eigen_PC
Benign
-0.60
FATHMM_MKL
Benign
0.25
N
LIST_S2
Benign
0.62
T;T;T;.;T;T;T
M_CAP
Benign
0.019
T
MetaRNN
Benign
0.025
T;T;T;T;T;T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
-1.2
.;.;.;N;.;.;N
PhyloP100
2.3
PrimateAI
Uncertain
0.53
T
PROVEAN
Benign
0.55
N;N;.;.;N;N;.
REVEL
Benign
0.087
Sift
Benign
1.0
T;T;.;.;T;T;.
Polyphen
0.0
.;.;.;B;.;.;B
Vest4
0.079
MVP
0.32
MPC
0.069
ClinPred
0.011
T
GERP RS
0.34
Mutation Taster
=85/15
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: rs774747865; hg19: chr2-179431787; API