2-178535442-T-C

Variant summary

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

The NM_001267550.2(TTN):​c.101173A>G​(p.Ile33725Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000192 in 1,613,846 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict 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. I33725T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

1
3
13

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 8.02

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 -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.22166127).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.101173A>G p.Ile33725Val missense_variant Exon 358 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.101173A>G p.Ile33725Val missense_variant Exon 358 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152260
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:
0.0000121
AC:
3
AN:
248878
AF XY:
0.0000148
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000290
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000177
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000205
AC:
30
AN:
1461586
Hom.:
0
Cov.:
38
AF XY:
0.0000206
AC XY:
15
AN XY:
727080
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33468
American (AMR)
AF:
0.0000224
AC:
1
AN:
44712
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39694
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53382
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000243
AC:
27
AN:
1111802
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60372
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
2
4
7
9
11
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:
0.00000657
AC:
1
AN:
152260
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74390
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41472
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68046
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000659
Hom.:
0
Bravo
AF:
0.0000302

ClinVar

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

Submissions by phenotype

not provided Uncertain:1
Mar 29, 2018
Athena Diagnostics
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
0.11
BayesDel_addAF
Benign
-0.20
T
BayesDel_noAF
Benign
-0.44
CADD
Benign
18
DANN
Benign
0.88
Eigen
Uncertain
0.28
Eigen_PC
Uncertain
0.43
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Benign
0.84
T;T;T;.;T;T;T
M_CAP
Benign
0.015
T
MetaRNN
Benign
0.22
T;T;T;T;T;T;T
MetaSVM
Benign
-0.87
T
MutationAssessor
Benign
1.3
.;.;.;L;.;.;L
PhyloP100
8.0
PrimateAI
Uncertain
0.51
T
PROVEAN
Benign
-0.61
N;N;.;.;N;N;.
REVEL
Benign
0.18
Sift
Benign
0.23
T;T;.;.;T;T;.
Polyphen
0.42
.;.;.;B;.;.;B
Vest4
0.20
MVP
0.49
MPC
0.12
ClinPred
0.23
T
GERP RS
5.6
Mutation Taster
=64/36
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: rs878900245; hg19: chr2-179400169; API