chr2-178605515-A-G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 1P and 1B. PP3BP6

The NM_001267550.2(TTN):​c.53780T>C​(p.Leu17927Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000161 in 1,612,316 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: š‘“ 0.000086 ( 0 hom., cov: 32)
Exomes š‘“: 0.00017 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

10
4
3

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6B:2

Conservation

PhyloP100: 9.27

Publications

1 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: Uncertain_significance. The variant received 0 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.826
BP6
Variant 2-178605515-A-G is Benign according to our data. Variant chr2-178605515-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 202710.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.53780T>C p.Leu17927Pro missense_variant Exon 279 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.53780T>C p.Leu17927Pro missense_variant Exon 279 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.0000855
AC:
13
AN:
151972
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.0000942
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000132
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000145
AC:
36
AN:
248156
AF XY:
0.000141
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000580
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.000232
Gnomad NFE exome
AF:
0.000258
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000168
AC:
246
AN:
1460344
Hom.:
0
Cov.:
32
AF XY:
0.000175
AC XY:
127
AN XY:
726432
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33390
American (AMR)
AF:
0.0000448
AC:
2
AN:
44688
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26086
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39596
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86150
European-Finnish (FIN)
AF:
0.000281
AC:
15
AN:
53392
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5754
European-Non Finnish (NFE)
AF:
0.000200
AC:
222
AN:
1110986
Other (OTH)
AF:
0.000116
AC:
7
AN:
60302
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.484
Heterozygous variant carriers
0
17
34
52
69
86
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
151972
Hom.:
0
Cov.:
32
AF XY:
0.0000674
AC XY:
5
AN XY:
74196
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41422
American (AMR)
AF:
0.000131
AC:
2
AN:
15244
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5136
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.0000942
AC:
1
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000132
AC:
9
AN:
67936
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.529
Heterozygous variant carriers
0
1
2
4
5
6
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:
0.000245
Hom.:
0
Bravo
AF:
0.000110
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.000259
AC:
1
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000243
AC:
2
ExAC
AF:
0.000182
AC:
22

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:6Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:3
Feb 11, 2021
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 08, 2017
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Nov 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

TTN: PM2 -

not specified Uncertain:1Benign:2
Mar 24, 2025
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: TTN c.46076T>C (p.Leu15359Pro) results in a non-conservative amino acid change in the encoded protein sequence. Four of four in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00015 in 248156 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in TTN causing Dilated Cardiomyopathy (0.00015 vs 0.00039), allowing no conclusion about variant significance. c.46076T>C has been reported in the literature in a case of early unexplained sudden death of an individual who was found to have Right Ventricular Cardiomyopathy upon autopsy, however, multiple variants in cardiac-related genes were reported and segregation data was not available (Salfati_2019). This report does not provide unequivocal conclusions about association of the variant with Dilated Cardiomyopathy. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 31847883). ClinVar contains an entry for this variant (Variation ID: 202710). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Feb 08, 2018
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

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

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Nov 27, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Uncertain:1
Jan 02, 2020
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.L8862P variant (also known as c.26585T>C), located in coding exon 106 of the TTN gene, results from a T to C substitution at nucleotide position 26585. The leucine at codon 8862 is replaced by proline, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.99
BayesDel_addAF
Uncertain
0.069
T
BayesDel_noAF
Pathogenic
0.16
CADD
Benign
23
DANN
Benign
0.94
Eigen
Pathogenic
1.0
Eigen_PC
Pathogenic
0.94
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Benign
0.82
T;T;T;.;T;T;T
M_CAP
Uncertain
0.087
D
MetaRNN
Pathogenic
0.83
D;D;D;D;D;D;D
MetaSVM
Pathogenic
0.93
D
MutationAssessor
Pathogenic
4.2
.;.;.;H;.;.;H
PhyloP100
9.3
PrimateAI
Uncertain
0.69
T
PROVEAN
Pathogenic
-5.7
D;D;.;.;D;D;.
REVEL
Pathogenic
0.91
Sift
Uncertain
0.0010
D;D;.;.;D;D;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.68
MVP
0.94
MPC
0.59
ClinPred
0.25
T
GERP RS
5.7
Mutation Taster
=57/43
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs369678018; hg19: chr2-179470242; API