chr2-178789404-T-C

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_StrongBP6

The NM_001267550.2(TTN):​c.2032A>G​(p.Thr678Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000527 in 1,613,446 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/19 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. T678T) has been classified as Likely benign.

Frequency

Genomes: š‘“ 0.000039 ( 0 hom., cov: 32)
Exomes š‘“: 0.000054 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

17

Clinical Significance

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

Conservation

PhyloP100: 1.01

Publications

2 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 Gene-Disease associations (from GenCC):
  • dilated cardiomyopathy
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • dilated cardiomyopathy 1G
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
  • early-onset myopathy with fatal cardiomyopathy
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, G2P
  • TTN-related myopathy
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • myopathy, myofibrillar, 9, with early respiratory failure
    Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, ClinGen, Ambry Genetics
  • tibial muscular dystrophy
    Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen, Orphanet
  • autosomal recessive limb-girdle muscular dystrophy type 2J
    Inheritance: AR Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Orphanet
  • hypertrophic cardiomyopathy 9
    Inheritance: AD Classification: MODERATE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia
  • familial isolated dilated cardiomyopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • autosomal recessive centronuclear myopathy
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • childhood-onset progressive contractures-limb-girdle weakness-muscle dystrophy syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • arrhythmogenic right ventricular cardiomyopathy
    Inheritance: AD Classification: LIMITED Submitted by: ClinGen
  • congenital myopathy
    Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
  • hereditary skeletal muscle disorder
    Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
  • hypertrophic cardiomyopathy
    Inheritance: AD Classification: LIMITED Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -5 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.0465658).
BP6
Variant 2-178789404-T-C is Benign according to our data. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716. Variant chr2-178789404-T-C is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 238716.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.2032A>G p.Thr678Ala missense_variant Exon 13 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7
TTNNM_133379.5 linkc.2032A>G p.Thr678Ala missense_variant Exon 13 of 46 ENST00000360870.10 NP_596870.2 Q8WZ42-6Q7Z3B7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.2032A>G p.Thr678Ala missense_variant Exon 13 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7
TTNENST00000360870.10 linkc.2032A>G p.Thr678Ala missense_variant Exon 13 of 46 5 NM_133379.5 ENSP00000354117.4 Q8WZ42-6

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152132
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000724
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:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251016
AF XY:
0.00000737
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000882
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000541
AC:
79
AN:
1461314
Hom.:
0
Cov.:
31
AF XY:
0.0000578
AC XY:
42
AN XY:
726956
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33452
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26116
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39638
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86248
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5760
European-Non Finnish (NFE)
AF:
0.0000702
AC:
78
AN:
1111600
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60366
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.455
Heterozygous variant carriers
0
5
10
14
19
24
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.0000394
AC:
6
AN:
152132
Hom.:
0
Cov.:
32
AF XY:
0.0000404
AC XY:
3
AN XY:
74328
show subpopulations
African (AFR)
AF:
0.0000724
AC:
3
AN:
41446
American (AMR)
AF:
0.00
AC:
0
AN:
15274
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3462
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
67980
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.583
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.0000847
Hom.:
0
Bravo
AF:
0.0000378
EpiCase
AF:
0.0000545
EpiControl
AF:
0.0000593

ClinVar

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

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Feb 08, 2016
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Nov 11, 2020
Mayo Clinic Laboratories, Mayo Clinic
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Benign:1
Nov 09, 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
0.069
BayesDel_addAF
Benign
-0.33
T
BayesDel_noAF
Benign
-0.71
CADD
Benign
14
DANN
Benign
0.84
Eigen
Benign
-0.70
Eigen_PC
Benign
-0.49
FATHMM_MKL
Benign
0.0075
N
LIST_S2
Benign
0.47
T;T;T;.;T;T;T;T;T
M_CAP
Benign
0.0040
T
MetaRNN
Benign
0.047
T;T;T;T;T;T;T;T;T
MetaSVM
Benign
-1.0
T
PhyloP100
1.0
PrimateAI
Benign
0.28
T
PROVEAN
Benign
-0.42
N;N;.;.;N;N;.;N;N
REVEL
Benign
0.061
Sift
Benign
0.99
T;T;.;.;T;T;.;T;T
Sift4G
Benign
0.58
.;.;.;.;.;.;.;T;.
Polyphen
0.0
.;.;.;B;.;.;B;B;.
Vest4
0.036
MutPred
0.34
Gain of phosphorylation at T675 (P = 0.0877);.;Gain of phosphorylation at T675 (P = 0.0877);Gain of phosphorylation at T675 (P = 0.0877);.;.;Gain of phosphorylation at T675 (P = 0.0877);Gain of phosphorylation at T675 (P = 0.0877);.;
MVP
0.055
MPC
0.082
ClinPred
0.037
T
GERP RS
4.1
Mutation Taster
=81/19
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: rs878854290; hg19: chr2-179654131; COSMIC: COSV60350464; API