2-178587949-A-G
Variant names: 
Variant summary
Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BP4
The NM_001267550.2(TTN):c.63458T>C(p.Ile21153Thr) variant causes a missense change. The variant allele was found at a frequency of 0.0000186 in 1,610,122 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).
Frequency
 Genomes: 𝑓 0.000033   (  0   hom.,  cov: 32) 
 Exomes 𝑓:  0.000017   (  0   hom.  ) 
Consequence
 TTN
NM_001267550.2 missense
NM_001267550.2 missense
Scores
 6
 11
Clinical Significance
Conservation
 PhyloP100:  7.04  
Publications
0 publications found 
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] 
Genome browser will be placed here
ACMG classification
Classification was made for transcript
Our verdict: Likely_benign. The variant received -1 ACMG points.
BP4
Computational evidence support a benign effect (MetaRNN=0.27729565). 
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt | 
|---|---|---|---|---|---|---|---|---|
| TTN | NM_001267550.2 | c.63458T>C | p.Ile21153Thr | missense_variant | Exon 305 of 363 | ENST00000589042.5 | NP_001254479.2 | 
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt | 
|---|---|---|---|---|---|---|---|---|---|---|
| TTN | ENST00000589042.5 | c.63458T>C | p.Ile21153Thr | missense_variant | Exon 305 of 363 | 5 | NM_001267550.2 | ENSP00000467141.1 | 
Frequencies
GnomAD3 genomes  0.0000329  AC: 5AN: 152014Hom.:  0  Cov.: 32 show subpopulations 
GnomAD3 genomes 
 AF: 
AC: 
5
AN: 
152014
Hom.: 
Cov.: 
32
Gnomad AFR 
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Gnomad NFE 
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Gnomad OTH 
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GnomAD2 exomes  AF:  0.0000247  AC: 6AN: 242746 AF XY:  0.0000152   show subpopulations 
GnomAD2 exomes 
 AF: 
AC: 
6
AN: 
242746
 AF XY: 
Gnomad AFR exome 
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Gnomad ASJ exome 
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Gnomad OTH exome 
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GnomAD4 exome  AF:  0.0000171  AC: 25AN: 1458108Hom.:  0  Cov.: 33 AF XY:  0.0000152  AC XY: 11AN XY: 725162 show subpopulations 
GnomAD4 exome 
 AF: 
AC: 
25
AN: 
1458108
Hom.: 
Cov.: 
33
 AF XY: 
AC XY: 
11
AN XY: 
725162
show subpopulations 
African (AFR) 
 AF: 
AC: 
1
AN: 
33404
American (AMR) 
 AF: 
AC: 
0
AN: 
44308
Ashkenazi Jewish (ASJ) 
 AF: 
AC: 
0
AN: 
25974
East Asian (EAS) 
 AF: 
AC: 
0
AN: 
39340
South Asian (SAS) 
 AF: 
AC: 
4
AN: 
85842
European-Finnish (FIN) 
 AF: 
AC: 
0
AN: 
53180
Middle Eastern (MID) 
 AF: 
AC: 
0
AN: 
5746
European-Non Finnish (NFE) 
 AF: 
AC: 
20
AN: 
1110086
Other (OTH) 
 AF: 
AC: 
0
AN: 
60228
 Allele Balance Distribution 
 Red line indicates average allele balance 
 Average allele balance: 0.479 
Heterozygous variant carriers
 0 
 1 
 3 
 4 
 6 
 7 
 0.00 
 0.20 
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 0.60 
 0.80 
 0.95 
Allele balance
Age Distribution
Exome Het
Variant carriers
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 <30 
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 65-70 
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 >80 
Age
GnomAD4 genome  0.0000329  AC: 5AN: 152014Hom.:  0  Cov.: 32 AF XY:  0.0000404  AC XY: 3AN XY: 74212 show subpopulations 
GnomAD4 genome 
 AF: 
AC: 
5
AN: 
152014
Hom.: 
Cov.: 
32
 AF XY: 
AC XY: 
3
AN XY: 
74212
show subpopulations 
African (AFR) 
 AF: 
AC: 
0
AN: 
41428
American (AMR) 
 AF: 
AC: 
0
AN: 
15254
Ashkenazi Jewish (ASJ) 
 AF: 
AC: 
0
AN: 
3468
East Asian (EAS) 
 AF: 
AC: 
0
AN: 
5144
South Asian (SAS) 
 AF: 
AC: 
0
AN: 
4820
European-Finnish (FIN) 
 AF: 
AC: 
0
AN: 
10618
Middle Eastern (MID) 
 AF: 
AC: 
0
AN: 
316
European-Non Finnish (NFE) 
 AF: 
AC: 
5
AN: 
67962
Other (OTH) 
 AF: 
AC: 
0
AN: 
2092
 Allele Balance Distribution 
 Red line indicates average allele balance 
 Average allele balance: 0.525 
Heterozygous variant carriers
 0 
 1 
 1 
 2 
 2 
 3 
 0.00 
 0.20 
 0.40 
 0.60 
 0.80 
 0.95 
Allele balance
Age Distribution
Genome Het
Variant carriers
 0 
 2 
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 10 
 <30 
 30-35 
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 60-65 
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Age
Alfa 
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Hom.: 
Bravo 
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ExAC 
 AF: 
AC: 
5
ClinVar
Significance: Uncertain significance 
Submissions summary: Uncertain:4 
Revision: criteria provided, multiple submitters, no conflicts
LINK: link 
Submissions by phenotype
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G    Uncertain:1 
Dec 12, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing
- -
Cardiomyopathy    Uncertain:1 
Apr 12, 2018
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing
- -
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1838244:Tibial muscular dystrophy;C1858763:Dilated cardiomyopathy 1G;C1861065:Hypertrophic cardiomyopathy 9;C1863599:Myopathy, myofibrillar, 9, with early respiratory failure;C2673677:Early-onset myopathy with fatal cardiomyopathy    Uncertain:1 
Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing
- -
not provided    Uncertain:1 
Dec 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing
TTN: PM2 -
Computational scores
Source: 
Name
Calibrated prediction
Score
Prediction
 AlphaMissense 
 Benign 
 BayesDel_addAF 
 Benign 
T 
 BayesDel_noAF 
 Benign 
 DANN 
 Benign 
 Eigen 
 Uncertain 
 Eigen_PC 
 Uncertain 
 FATHMM_MKL 
 Uncertain 
D 
 LIST_S2 
 Uncertain 
D;D;D;.;T;D;T 
 M_CAP 
 Benign 
T 
 MetaRNN 
 Benign 
T;T;T;T;T;T;T 
 MetaSVM 
 Benign 
T 
 MutationAssessor 
 Benign 
.;.;.;N;.;.;N 
 PhyloP100 
 PrimateAI 
 Uncertain 
T 
 PROVEAN 
 Uncertain 
D;D;.;.;D;D;. 
 REVEL 
 Benign 
 Sift 
 Benign 
T;T;.;.;T;T;. 
 Polyphen 
 0.78 
.;.;.;P;.;.;P 
 Vest4 
 MVP 
 MPC 
 0.24 
 ClinPred 
T 
 GERP RS 
Splicing
Name
Calibrated prediction
Score
Prediction
 SpliceAI score (max) 
Details are displayed if max score is > 0.2
 Find out detailed SpliceAI scores and Pangolin per-transcript scores at 
Publications
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