rs374631591

Variant summary

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

The NM_001267550.2(TTN):​c.12653T>C​(p.Ile4218Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000886 in 1,613,744 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).

Frequency

Genomes: 𝑓 0.00012 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000086 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

16

Clinical Significance

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

Conservation

PhyloP100: -0.340

Publications

1 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-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 was made for transcript

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

BP4
Computational evidence support a benign effect (MetaRNN=0.024094224).
BP6
Variant 2-178740580-A-G is Benign according to our data. Variant chr2-178740580-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 47828.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.12653T>C p.Ile4218Thr missense_variant Exon 48 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.12653T>C p.Ile4218Thr missense_variant Exon 48 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.000118
AC:
18
AN:
152156
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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:
0.000235
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.0000724
AC:
18
AN:
248726
AF XY:
0.0000667
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000290
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000142
Gnomad OTH exome
AF:
0.000166
GnomAD4 exome
AF:
0.0000855
AC:
125
AN:
1461588
Hom.:
0
Cov.:
32
AF XY:
0.0000811
AC XY:
59
AN XY:
727078
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33472
American (AMR)
AF:
0.0000224
AC:
1
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39678
South Asian (SAS)
AF:
0.0000348
AC:
3
AN:
86256
European-Finnish (FIN)
AF:
0.0000187
AC:
1
AN:
53392
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5768
European-Non Finnish (NFE)
AF:
0.000103
AC:
114
AN:
1111806
Other (OTH)
AF:
0.0000828
AC:
5
AN:
60368
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.487
Heterozygous variant carriers
0
10
20
29
39
49
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:
0.000118
AC:
18
AN:
152156
Hom.:
0
Cov.:
32
AF XY:
0.000121
AC XY:
9
AN XY:
74330
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41442
American (AMR)
AF:
0.0000655
AC:
1
AN:
15274
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5178
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000235
AC:
16
AN:
68022
Other (OTH)
AF:
0.000478
AC:
1
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.497
Heterozygous variant carriers
0
1
2
4
5
6
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:
0.000159
Hom.:
0
Bravo
AF:
0.000102
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000122
AC:
1
ExAC
AF:
0.0000579
AC:
7
EpiCase
AF:
0.000164
EpiControl
AF:
0.000178

ClinVar

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

Submissions by phenotype

not provided Uncertain:1Benign:1
Oct 15, 2020
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

May 23, 2017
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1
Mar 30, 2021
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant classified as Uncertain Significance - Favor Benign. The p.Ile3980Thr variant in TTN has not been previously reported in individuals with cardiomyopathy but has been identified in 0.02% (20/127992) of European chromosomes by gnomAD (http://gnomad.broadinstitute.org). Computational prediction tools and conservation analyses suggest that this variant may not impact the protein, though this information is not predictive enough to rule out pathogenicity. In summary, while the clinical significance of this variant is uncertain, these data suggest that it is more likely to be benign. ACMG/AMP Criteria applied: BS1_Supporting, BP4. -

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

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.061
BayesDel_addAF
Benign
-0.47
T
BayesDel_noAF
Benign
-0.66
CADD
Benign
7.7
DANN
Benign
0.68
Eigen
Benign
-1.2
Eigen_PC
Benign
-1.1
FATHMM_MKL
Benign
0.010
N
LIST_S2
Benign
0.63
T;T;.;T;T;T
M_CAP
Benign
0.011
T
MetaRNN
Benign
0.024
T;T;T;T;T;T
MetaSVM
Benign
-1.0
T
PhyloP100
-0.34
PrimateAI
Benign
0.24
T
PROVEAN
Benign
0.87
N;.;.;N;N;.
REVEL
Benign
0.057
Sift
Benign
1.0
T;.;.;T;T;.
Vest4
0.015
MVP
0.11
MPC
0.11
ClinPred
0.013
T
GERP RS
-2.4
Mutation Taster
=94/6
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: rs374631591; hg19: chr2-179605307; API