2-178588782-A-G

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_StrongBP6BP7

The NM_001267550.2(TTN):​c.62943T>C​(p.Thr20981Thr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000423 in 1,613,382 control chromosomes in the GnomAD database, including 1 homozygotes. 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: š‘“ 0.00030 ( 0 hom., cov: 32)
Exomes š‘“: 0.00044 ( 1 hom. )

Consequence

TTN
NM_001267550.2 synonymous

Scores

2

Clinical Significance

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

Conservation

PhyloP100: -0.00600
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 -6 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.56).
BP6
Variant 2-178588782-A-G is Benign according to our data. Variant chr2-178588782-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 165912.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=6, Benign=4, Uncertain_significance=4}.
BP7
Synonymous conserved (PhyloP=-0.006 with no splicing effect.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.62943T>C p.Thr20981Thr synonymous_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.62943T>C p.Thr20981Thr synonymous_variant Exon 304 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.000302
AC:
46
AN:
152090
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000217
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:
0.000529
Gnomad OTH
AF:
0.000478
GnomAD3 exomes
AF:
0.000197
AC:
49
AN:
248362
Hom.:
0
AF XY:
0.000200
AC XY:
27
AN XY:
134744
show subpopulations
Gnomad AFR exome
AF:
0.000194
Gnomad AMR exome
AF:
0.0000290
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:
0.000400
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000436
AC:
637
AN:
1461174
Hom.:
1
Cov.:
33
AF XY:
0.000398
AC XY:
289
AN XY:
726872
show subpopulations
Gnomad4 AFR exome
AF:
0.000149
Gnomad4 AMR exome
AF:
0.0000224
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:
0.000525
Gnomad4 OTH exome
AF:
0.000779
GnomAD4 genome
AF:
0.000302
AC:
46
AN:
152208
Hom.:
0
Cov.:
32
AF XY:
0.000175
AC XY:
13
AN XY:
74408
show subpopulations
Gnomad4 AFR
AF:
0.000217
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000530
Gnomad4 OTH
AF:
0.000473
Alfa
AF:
0.000278
Hom.:
0
Bravo
AF:
0.000287
EpiCase
AF:
0.000273
EpiControl
AF:
0.000237

ClinVar

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

Submissions by phenotype

not specified Benign:4
Apr 24, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Sep 10, 2015
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

p.Thr18413Thr in exon 253 of TTN: This variant is not expected to have clinical significance because it does not alter an amino acid residue and is not located within the splice consensus sequence. It has been identified in 20/66520 Europea n chromosomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinsti tute.org; dbSNP rs184863287). -

Apr 02, 2015
GeneDx
Significance: 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. -

Dec 12, 2019
Athena Diagnostics
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

not provided Uncertain:1Benign:1
Sep 01, 2022
CeGaT Center for Human Genetics Tuebingen
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

TTN: BP4, BP7 -

Sep 11, 2015
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 Uncertain:1
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Dilated cardiomyopathy 1G Uncertain:1
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Early-onset myopathy with fatal cardiomyopathy Uncertain:1
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

TTN-related disorder Benign:1
Feb 21, 2019
PreventionGenetics, part of Exact Sciences
Significance: Likely benign
Review Status: no assertion criteria provided
Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
Jan 22, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Cardiomyopathy Benign:1
May 16, 2023
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Tibial muscular dystrophy Benign:1
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Myopathy, myofibrillar, 9, with early respiratory failure Benign:1
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Cardiovascular phenotype Benign:1
Oct 24, 2013
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: 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
BayesDel_noAF
Benign
-0.56
CADD
Benign
0.33
DANN
Benign
0.77

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: rs184863287; hg19: chr2-179453509; API