rs373351577

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM1BP4_ModerateBP6

The NM_001267550.2(TTN):​c.56960T>C​(p.Ile18987Thr) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000329 in 1,611,158 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I18987V) has been classified as Uncertain significance.

Frequency

Genomes: š‘“ 0.000033 ( 0 hom., cov: 32)
Exomes š‘“: 0.000033 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense, splice_region

Scores

1
2
14
Splicing: ADA: 0.0002485
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:2

Conservation

PhyloP100: 6.24

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.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 5 uncertain in NM_001267550.2
BP4
Computational evidence support a benign effect (MetaRNN=0.17541069).
BP6
Variant 2-178598750-A-G is Benign according to our data. Variant chr2-178598750-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 467295.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.56960T>C p.Ile18987Thr missense_variant, splice_region_variant Exon 291 of 363 ENST00000589042.5 NP_001254479.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.56960T>C p.Ile18987Thr missense_variant, splice_region_variant Exon 291 of 363 5 NM_001267550.2 ENSP00000467141.1

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152086
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:
0.0000735
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000366
AC:
9
AN:
245916
AF XY:
0.0000150
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000118
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000561
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000269
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000329
AC:
48
AN:
1459072
Hom.:
0
Cov.:
33
AF XY:
0.0000317
AC XY:
23
AN XY:
725836
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33240
American (AMR)
AF:
0.0000907
AC:
4
AN:
44112
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26048
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39632
South Asian (SAS)
AF:
0.0000117
AC:
1
AN:
85632
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53382
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5748
European-Non Finnish (NFE)
AF:
0.0000360
AC:
40
AN:
1111018
Other (OTH)
AF:
0.0000332
AC:
2
AN:
60260
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.518
Heterozygous variant carriers
0
3
6
10
13
16
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:
152086
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74282
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41436
American (AMR)
AF:
0.00
AC:
0
AN:
15262
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5156
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000735
AC:
5
AN:
67988
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
2
2
3
4
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:
0.0000282
Hom.:
0
Bravo
AF:
0.0000189
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000245
AC:
2
ExAC
AF:
0.0000331
AC:
4
EpiCase
AF:
0.0000546
EpiControl
AF:
0.0000594

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:3Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:1
Aug 17, 2018
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jun 07, 2017
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Jun 09, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Uncertain:1
Apr 12, 2018
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.I9922T variant (also known as c.29765T>C), located in coding exon 118 of the TTN gene, results from a T to C substitution at nucleotide position 29765. The isoleucine at codon 9922 is replaced by threonine, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species, and threonine is the reference amino acid in other vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

not specified Benign:1
Apr 09, 2025
Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.20
BayesDel_addAF
Benign
-0.22
T
BayesDel_noAF
Benign
-0.33
CADD
Benign
17
DANN
Benign
0.82
Eigen
Benign
-0.00054
Eigen_PC
Benign
0.14
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Benign
0.78
T;T;T;.;T;T;T
M_CAP
Benign
0.085
D
MetaRNN
Benign
0.18
T;T;T;T;T;T;T
MetaSVM
Benign
-0.66
T
MutationAssessor
Uncertain
2.0
.;.;.;M;.;.;M
PhyloP100
6.2
PrimateAI
Benign
0.38
T
PROVEAN
Uncertain
-3.2
D;D;.;.;D;D;.
REVEL
Benign
0.14
Sift
Benign
0.057
T;D;.;.;D;D;.
Polyphen
0.0
.;.;.;B;.;.;B
Vest4
0.45
MVP
0.38
MPC
0.11
ClinPred
0.080
T
GERP RS
4.8
Mutation Taster
=75/25
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.00025
dbscSNV1_RF
Benign
0.0080
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: rs373351577; hg19: chr2-179463477; API