rs201490050

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 0P and 3B. BP4_ModerateBP6

The NM_001267550.2(TTN):​c.81302G>T​(p.Gly27101Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000645 in 1,613,082 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00031 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000039 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

8
4
5

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6B:3O:1

Conservation

PhyloP100: 7.86
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 made for transcript

Verdict is Likely_benign. Variant got -3 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.21483365).
BP6
Variant 2-178564830-C-A is Benign according to our data. Variant chr2-178564830-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 202905.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=3, Uncertain_significance=4, not_provided=1}. Variant chr2-178564830-C-A is described in Lovd as [Likely_benign].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.81302G>T p.Gly27101Val missense_variant Exon 326 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.81302G>T p.Gly27101Val missense_variant Exon 326 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.000309
AC:
47
AN:
152094
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00106
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:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.000478
GnomAD3 exomes
AF:
0.0000689
AC:
17
AN:
246672
Hom.:
0
AF XY:
0.0000672
AC XY:
9
AN XY:
133876
show subpopulations
Gnomad AFR exome
AF:
0.00110
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000390
AC:
57
AN:
1460870
Hom.:
0
Cov.:
37
AF XY:
0.0000330
AC XY:
24
AN XY:
726674
show subpopulations
Gnomad4 AFR exome
AF:
0.00164
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00
Gnomad4 OTH exome
AF:
0.0000331
GnomAD4 genome
AF:
0.000309
AC:
47
AN:
152212
Hom.:
0
Cov.:
33
AF XY:
0.000242
AC XY:
18
AN XY:
74404
show subpopulations
Gnomad4 AFR
AF:
0.00106
Gnomad4 AMR
AF:
0.000131
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.000473
Alfa
AF:
0.0000527
Hom.:
0
Bravo
AF:
0.000370
ESP6500AA
AF:
0.00107
AC:
4
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000828
AC:
10

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:6Benign:3Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:4Other:1
Oct 26, 2022
Mayo Clinic Laboratories, Mayo Clinic
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

BS1 -

Apr 14, 2014
GeneDx
Significance: not provided
Review Status: no classification provided
Collection Method: clinical testing

- -

Jan 14, 2019
Revvity Omics, Revvity
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Sep 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Apr 25, 2017
Eurofins Ntd Llc (ga)
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

TTN-related disorder Uncertain:1
Oct 28, 2023
PreventionGenetics, part of Exact Sciences
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing

The TTN c.81302G>T variant is predicted to result in the amino acid substitution p.Gly27101Val. This variant was reported in an individual with dilated cardiomyopathy (Table S3, Mazzarotto et al. 2020. PubMed ID: 31983221). This variant is reported in 0.11% of alleles in individuals of African descent in gnomAD (http://gnomad.broadinstitute.org/variant/2-179429557-C-A). Although we suspect that this variant may be benign, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Left ventricular hypertrophy Uncertain:1
Nov 04, 2015
Clinical Molecular Genetics Laboratory, Johns Hopkins All Children's Hospital
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

not specified Benign:1
Mar 22, 2021
Athena Diagnostics
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 Benign:1
Dec 12, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Cardiovascular phenotype Benign:1
Jan 16, 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
Pathogenic
0.96
BayesDel_addAF
Benign
-0.075
T
BayesDel_noAF
Uncertain
0.070
CADD
Benign
21
DANN
Benign
0.85
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
1.0
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.98
D;D;D;.;D;D;D
M_CAP
Benign
0.056
D
MetaRNN
Benign
0.21
T;T;T;T;T;T;T
MetaSVM
Uncertain
0.49
D
MutationAssessor
Pathogenic
3.9
.;.;.;H;.;.;H
PrimateAI
Uncertain
0.55
T
PROVEAN
Pathogenic
-6.6
D;D;.;.;D;D;.
REVEL
Uncertain
0.63
Sift
Pathogenic
0.0
D;D;.;.;D;D;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.53
MVP
0.71
MPC
0.52
ClinPred
0.34
T
GERP RS
6.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs201490050; hg19: chr2-179429557; COSMIC: COSV104641657; API