rs370687831

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4_StrongBP6

The NM_001267550.2(TTN):​c.63329C>T​(p.Ala21110Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000122 in 1,612,854 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/19 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. A21110A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000085 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00013 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

17

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:10B:7

Conservation

PhyloP100: 1.40
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 -5 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.034549713).
BP6
Variant 2-178588078-G-A is Benign according to our data. Variant chr2-178588078-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 228120.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Benign=2, Uncertain_significance=10}. Variant chr2-178588078-G-A is described in Lovd as [Likely_benign].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.63329C>T p.Ala21110Val missense_variant Exon 305 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.63329C>T p.Ala21110Val missense_variant Exon 305 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.0000856
AC:
13
AN:
151952
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000483
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.000137
AC:
34
AN:
247974
Hom.:
0
AF XY:
0.000186
AC XY:
25
AN XY:
134526
show subpopulations
Gnomad AFR exome
AF:
0.0000647
Gnomad AMR exome
AF:
0.0000871
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:
0.000268
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000126
AC:
184
AN:
1460784
Hom.:
0
Cov.:
33
AF XY:
0.000144
AC XY:
105
AN XY:
726658
show subpopulations
Gnomad4 AFR exome
AF:
0.0000598
Gnomad4 AMR exome
AF:
0.0000671
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000232
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.000156
Gnomad4 OTH exome
AF:
0.0000663
GnomAD4 genome
AF:
0.0000855
AC:
13
AN:
152070
Hom.:
0
Cov.:
32
AF XY:
0.000108
AC XY:
8
AN XY:
74322
show subpopulations
Gnomad4 AFR
AF:
0.0000482
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000207
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000818
Hom.:
0
Bravo
AF:
0.000106
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000600
AC:
5
ExAC
AF:
0.000116
AC:
14
EpiCase
AF:
0.000109
EpiControl
AF:
0.000297

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:10Benign:7
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:4Benign:4
-
Clinical Genetics, Academic Medical Center
Significance: Likely benign
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

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

TTN: PM2, BP4 -

Sep 04, 2018
GeneDx
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Dec 29, 2023
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The TTN c.63329C>T; p.Ala21110Val variant (rs370687831; ClinVar Variation ID: 228120) is rare in the general population (<0.2% 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.Ala21110Val variant cannot be determined with certainty. -

Oct 25, 2023
Athena Diagnostics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Available data are insufficient to determine the clinical significance of the variant at this time. The frequency of this variant in the general population is higher than would generally be expected for pathogenic variants in this gene. (http://gnomad.broadinstitute.org) Computational tools disagree on the variant's effect on normal protein function. -

Aug 17, 2022
Mayo Clinic Laboratories, Mayo Clinic
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

BP4 -

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

- -

-
Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+
Significance: Likely benign
Review Status: no assertion criteria provided
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. -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Dec 29, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Cardiomyopathy Uncertain:1
Mar 11, 2019
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

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. -

Cardiovascular phenotype Uncertain:1
Nov 10, 2018
Ambry Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The p.A12045V variant (also known as c.36134C>T), located in coding exon 132 of the TTN gene, results from a C to T substitution at nucleotide position 36134. The alanine at codon 12045 is replaced by valine, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

not specified Benign:1
Mar 30, 2015
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

p.Ala18542Ala in exon 254 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 also been identified in 12/66476 E uropean chromosomes by the Exome Aggregation Consortium (ExAC, http://exac.broad institute.org; dbSNP rs370687831). -

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. -

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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.074
BayesDel_addAF
Benign
-0.37
T
BayesDel_noAF
Benign
-0.48
CADD
Benign
14
DANN
Benign
0.90
Eigen
Benign
-0.75
Eigen_PC
Benign
-0.67
FATHMM_MKL
Benign
0.085
N
LIST_S2
Benign
0.85
D;D;D;.;T;D;T
M_CAP
Benign
0.021
T
MetaRNN
Benign
0.035
T;T;T;T;T;T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
0.52
.;.;.;N;.;.;N
PrimateAI
Benign
0.28
T
PROVEAN
Benign
-2.0
N;N;.;.;N;N;.
REVEL
Benign
0.049
Sift
Benign
0.10
T;T;.;.;T;T;.
Polyphen
0.064
.;.;.;B;.;.;B
Vest4
0.18
MVP
0.14
MPC
0.090
ClinPred
0.015
T
GERP RS
2.4

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: rs370687831; hg19: chr2-179452805; COSMIC: COSV60181597; COSMIC: COSV60181597; API