rs201381085

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6

The NM_001267550.2(TTN):​c.68864G>C​(p.Gly22955Ala) variant causes a missense change. The variant allele was found at a frequency of 0.000273 in 1,596,118 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. G22955G) has been classified as Likely benign.

Frequency

Genomes: š‘“ 0.00032 ( 0 hom., cov: 32)
Exomes š‘“: 0.00027 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

3
4
10

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:11B:4

Conservation

PhyloP100: 4.69

Publications

8 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 -3 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.16587901).
BP6
Variant 2-178577471-C-G is Benign according to our data. Variant chr2-178577471-C-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 178195.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.68864G>C p.Gly22955Ala missense_variant Exon 324 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.68864G>C p.Gly22955Ala missense_variant Exon 324 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.000316
AC:
48
AN:
151792
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000969
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000592
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:
0.000515
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000259
AC:
63
AN:
243090
AF XY:
0.000250
show subpopulations
Gnomad AFR exome
AF:
0.0000648
Gnomad AMR exome
AF:
0.000439
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000379
Gnomad OTH exome
AF:
0.000846
GnomAD4 exome
AF:
0.000269
AC:
388
AN:
1444326
Hom.:
0
Cov.:
35
AF XY:
0.000268
AC XY:
192
AN XY:
715522
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33128
American (AMR)
AF:
0.000519
AC:
23
AN:
44334
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25794
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39224
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85412
European-Finnish (FIN)
AF:
0.0000198
AC:
1
AN:
50446
Middle Eastern (MID)
AF:
0.000350
AC:
2
AN:
5720
European-Non Finnish (NFE)
AF:
0.000324
AC:
357
AN:
1100638
Other (OTH)
AF:
0.0000839
AC:
5
AN:
59630
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.479
Heterozygous variant carriers
0
21
42
63
84
105
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
20
40
60
80
100
<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:
0.000316
AC:
48
AN:
151792
Hom.:
0
Cov.:
32
AF XY:
0.000216
AC XY:
16
AN XY:
74090
show subpopulations
African (AFR)
AF:
0.0000969
AC:
4
AN:
41292
American (AMR)
AF:
0.000592
AC:
9
AN:
15214
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5150
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4816
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10584
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000515
AC:
35
AN:
67954
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.517
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

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:
0.000400
Hom.:
0
Bravo
AF:
0.000291
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000366
AC:
3
ExAC
AF:
0.000232
AC:
28

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:11Benign:4
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:8Benign:1
Nov 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jun 09, 2016
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Oct 19, 2022
Mayo Clinic Laboratories, Mayo Clinic
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jul 19, 2023
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dec 22, 2020
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is associated with the following publications: (PMID: 27930701) -

Apr 26, 2019
Athena Diagnostics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

-
Clinical Genetics, Academic Medical Center
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

-
Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

not specified Uncertain:2Benign:1
Feb 18, 2016
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Gly20387Ala variant in TTN has been identified by our laboratory in one in dividual with DCM and in 20/65424 European chromosomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; dbSNP rs201381085). Computatio nal prediction tools and conservation analysis suggest that this variant may imp act the protein, though this information is not predictive enough to determine p athogenicity. In summary, the clinical significance of the p.Gly20387Ala variant is uncertain. -

May 26, 2019
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The TTN c.68864G>C; p.Gly22955Ala variant (rs201381085; ClinVar Variation ID: 178195) is rare in the general population (<1% allele frequency in the Genome Aggregation Database) and has not been reported in the medical literature in association with dilated cardiomyopathy (DCM) or other TTN-related disease. The clinical relevance of rare missense variants in this gene, which are identified on average once per individual sequenced in affected populations (Herman 2012), is not well understood. Yet, evidence suggests that the vast majority of such missense variants do not contribute to the clinical outcome of DCM (Begay 2015). Thus, the clinical significance of the p.Gly22955Ala variant cannot be determined with certainty. References: Begay RL et al. Role of Titin Missense Variants in Dilated Cardiomyopathy. J Am Heart Assoc. 2015 Nov 13;4(11). Herman DS et al. Truncations of titin causing dilated cardiomyopathy. N Engl J Med. 2012 Feb 16;366(7):619-28. Linke and Hamdani. Gigantic business: titin properties and function through thick and thin. Circ Res 2014; 114(6): 1052-1068. -

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 03, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiomyopathy Benign:1
Jul 05, 2021
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Benign:1
Mar 25, 2020
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.20
BayesDel_addAF
Benign
-0.32
T
BayesDel_noAF
Benign
-0.36
CADD
Benign
20
DANN
Benign
0.88
Eigen
Uncertain
0.68
Eigen_PC
Pathogenic
0.69
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.91
D;D;D;.;D;D;D
M_CAP
Benign
0.041
D
MetaRNN
Benign
0.17
T;T;T;T;T;T;T
MetaSVM
Benign
-0.71
T
MutationAssessor
Benign
1.8
.;.;.;L;.;.;L
PhyloP100
4.7
PrimateAI
Uncertain
0.54
T
PROVEAN
Pathogenic
-4.4
D;D;.;.;D;D;.
REVEL
Benign
0.26
Sift
Uncertain
0.024
D;T;.;.;T;T;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.40
MVP
0.15
MPC
0.43
ClinPred
0.069
T
GERP RS
5.6
Mutation Taster
=73/27
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: rs201381085; hg19: chr2-179442198; API