NM_001267550.2:c.16895T>C

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2BP4_ModerateBP6

The NM_001267550.2(TTN):​c.16895T>C​(p.Ile5632Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000187 in 1,604,208 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/19 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 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

2
14

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.09

Publications

2 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.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.18419197).
BP6
Variant 2-178732074-A-G is Benign according to our data. Variant chr2-178732074-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 179589.We mark this variant Likely_benign, oryginal submission is: [Conflicting_classifications_of_pathogenicity].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.16895T>C p.Ile5632Thr missense_variant Exon 57 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.16895T>C p.Ile5632Thr missense_variant Exon 57 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152188
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000482
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
GnomAD4 exome
AF:
6.89e-7
AC:
1
AN:
1452020
Hom.:
0
Cov.:
36
AF XY:
0.00
AC XY:
0
AN XY:
720640
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33248
American (AMR)
AF:
0.00
AC:
0
AN:
44368
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25674
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39534
South Asian (SAS)
AF:
0.00
AC:
0
AN:
84936
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53092
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5708
European-Non Finnish (NFE)
AF:
9.05e-7
AC:
1
AN:
1105546
Other (OTH)
AF:
0.00
AC:
0
AN:
59914
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152188
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74334
show subpopulations
African (AFR)
AF:
0.0000482
AC:
2
AN:
41460
American (AMR)
AF:
0.00
AC:
0
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68024
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
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:
0.0000189

ClinVar

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

Submissions by phenotype

not specified Uncertain:1
Mar 24, 2014
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 Ile4388Thr vari ant in TTN has not been previously reported in indivdiuals with cardiomyopathy o r in large population studies. Isoleucine (Ile) at position 4388 is not conserve d in evolution and multiple bird and fish species carry a threonine (Thr) at thi s position, supporting that this change may be tolerated. Computational predicti on tools also suggest that this variant may not impact the protein, though this information is not predictive enough to rule out pathogenicity. While the presen ce of the variant amino acid in other species supports that the Ile4388Thr varia nt is less likely to be disease-causing, additional studies are needed to fully assess its clinical significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.068
BayesDel_addAF
Uncertain
0.086
D
BayesDel_noAF
Benign
-0.11
CADD
Benign
21
DANN
Benign
0.84
Eigen
Benign
-0.11
Eigen_PC
Benign
0.15
FATHMM_MKL
Benign
0.73
D
LIST_S2
Benign
0.71
T;T;.;T
M_CAP
Benign
0.018
T
MetaRNN
Benign
0.18
T;T;T;T
MetaSVM
Benign
-0.98
T
PhyloP100
4.1
PrimateAI
Uncertain
0.52
T
PROVEAN
Benign
-1.7
N;.;.;.
REVEL
Benign
0.26
Sift
Benign
0.46
T;.;.;.
Polyphen
0.0030
.;.;B;B
Vest4
0.40
MutPred
0.44
.;.;Loss of stability (P = 0.019);Loss of stability (P = 0.019);
MVP
0.66
MPC
0.11
ClinPred
0.27
T
GERP RS
6.2
Mutation Taster
=68/32
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: rs727504971; hg19: chr2-179596801; COSMIC: COSV99045721; COSMIC: COSV99045721; API