rs558670891

Variant summary

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

The NM_001267550.2(TTN):​c.62030T>C​(p.Ile20677Thr) variant causes a missense change. The variant allele was found at a frequency of 0.0000359 in 1,613,508 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 0.000039 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000036 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

1
9
7

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:2O:1

Conservation

PhyloP100: 6.03
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=0.15533948).
BP6
Variant 2-178589695-A-G is Benign according to our data. Variant chr2-178589695-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 179416.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=2, not_provided=1}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.62030T>C p.Ile20677Thr missense_variant Exon 304 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.62030T>C p.Ile20677Thr missense_variant Exon 304 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.0000395
AC:
6
AN:
152062
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000965
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000414
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000484
AC:
12
AN:
248188
Hom.:
0
AF XY:
0.0000743
AC XY:
10
AN XY:
134596
show subpopulations
Gnomad AFR exome
AF:
0.0000646
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.000327
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000892
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000356
AC:
52
AN:
1461328
Hom.:
0
Cov.:
37
AF XY:
0.0000399
AC XY:
29
AN XY:
726948
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.000220
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000252
Gnomad4 OTH exome
AF:
0.0000497
GnomAD4 genome
AF:
0.0000394
AC:
6
AN:
152180
Hom.:
0
Cov.:
33
AF XY:
0.0000403
AC XY:
3
AN XY:
74374
show subpopulations
Gnomad4 AFR
AF:
0.0000962
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000415
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000386
Hom.:
0
Bravo
AF:
0.0000113
ExAC
AF:
0.0000414
AC:
5
Asia WGS
AF:
0.000289
AC:
1
AN:
3476

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:2Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2Other:1
Apr 08, 2014
GeneDx
Significance: not provided
Review Status: no classification provided
Collection Method: clinical testing

- -

Feb 21, 2023
Revvity Omics, Revvity
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Jan 05, 2016
Eurofins Ntd Llc (ga)
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

not specified Benign:1
Sep 22, 2020
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The p.Ile18109Thr variant in TTN is classified as likely benign because it has been identified in 0.03% (10/30594) of South Asian chromosomes by gnomAD (http://gnomad.broadinstitute.org). Computational prediction tools and conservation analysis do not provide strong support for or against an impact to the protein. ACMG/AMP Criteria applied: BS1. -

Cardiomyopathy Benign:1
Sep 01, 2021
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
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
Uncertain
0.53
BayesDel_addAF
Benign
-0.20
T
BayesDel_noAF
Benign
-0.22
CADD
Benign
22
DANN
Benign
0.85
Eigen
Uncertain
0.63
Eigen_PC
Pathogenic
0.67
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Uncertain
0.89
D;D;D;.;D;D;D
M_CAP
Benign
0.030
D
MetaRNN
Benign
0.16
T;T;T;T;T;T;T
MetaSVM
Benign
-0.46
T
MutationAssessor
Uncertain
2.8
.;.;.;M;.;.;M
PrimateAI
Uncertain
0.75
T
PROVEAN
Uncertain
-3.5
D;D;.;.;D;D;.
REVEL
Uncertain
0.31
Sift
Uncertain
0.0030
D;D;.;.;D;D;.
Polyphen
0.92
.;.;.;P;.;.;P
Vest4
0.43
MVP
0.59
MPC
0.31
ClinPred
0.21
T
GERP RS
6.1

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: rs558670891; hg19: chr2-179454422; API