chr2-178718084-G-A

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6

The NM_001267550.2(TTN):​c.24922C>T​(p.Pro8308Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000223 in 1,613,400 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/19 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 0.00014 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

4
12

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 2.41

Publications

0 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 -3 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.13394871).
BP6
Variant 2-178718084-G-A is Benign according to our data. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545. Variant chr2-178718084-G-A is described in CliVar as Conflicting_classifications_of_pathogenicity. Clinvar id is 504545.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.24922C>T p.Pro8308Ser missense_variant Exon 86 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.24922C>T p.Pro8308Ser missense_variant Exon 86 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.000138
AC:
21
AN:
152116
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000483
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:
0.00
Gnomad OTH
AF:
0.000479
GnomAD2 exomes
AF:
0.0000281
AC:
7
AN:
248672
AF XY:
0.0000148
show subpopulations
Gnomad AFR exome
AF:
0.000452
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000103
AC:
15
AN:
1461284
Hom.:
0
Cov.:
35
AF XY:
0.0000110
AC XY:
8
AN XY:
726930
show subpopulations
African (AFR)
AF:
0.000418
AC:
14
AN:
33456
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26126
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39694
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53206
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111708
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60358
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.482
Heterozygous variant carriers
0
2
4
5
7
9
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
AF:
0.000138
AC:
21
AN:
152116
Hom.:
0
Cov.:
33
AF XY:
0.000188
AC XY:
14
AN XY:
74292
show subpopulations
African (AFR)
AF:
0.000483
AC:
20
AN:
41434
American (AMR)
AF:
0.00
AC:
0
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67996
Other (OTH)
AF:
0.000479
AC:
1
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.492
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:
0.000285
Hom.:
0
Bravo
AF:
0.000200
ESP6500AA
AF:
0.000790
AC:
3
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000331
AC:
4

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Apr 29, 2016
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Pro7064Ser variant in TTN has not been previously reported in individuals with cardiomyopathy, but has been identified in 4/9800 African chromosomes by th e Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; dbSNP rs37 3770383). Computational prediction tools and conservation analysis do not provid e strong support for or against an impact to the protein. In summary, the clinic al significance of the p.Pro7064Ser variant is uncertain. -

not provided Uncertain:1
Jun 21, 2024
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The TTN c.24922C>T; p.Pro8308Ser variant (rs373770383; ClinVar Variation ID: 504545) 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.Pro8308Ser variant cannot be determined with certainty. References: Begay RL et al. Role of Titin Missense Variants in Dilated Cardiomyopathy. J Am Heart Assoc. 2015 Nov 13;4(11). PMID: 26567375. Herman DS et al. Truncations of titin causing dilated cardiomyopathy. N Engl J Med. 2012 Feb 16;366(7):619-28. PMID: 22335739. Linke WA and Hamdani N. Gigantic business: titin properties and function through thick and thin. Circ Res 2014; 114(6): 1052-1068. PMID: 24625729. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.24
BayesDel_addAF
Benign
-0.37
T
BayesDel_noAF
Benign
-0.40
CADD
Benign
21
DANN
Benign
0.90
Eigen
Benign
0.11
Eigen_PC
Uncertain
0.32
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Benign
0.69
T;T;.;T
M_CAP
Benign
0.027
D
MetaRNN
Benign
0.13
T;T;T;T
MetaSVM
Benign
-0.85
T
PhyloP100
2.4
PrimateAI
Uncertain
0.51
T
PROVEAN
Uncertain
-3.4
D;.;.;.
REVEL
Benign
0.18
Sift
Benign
0.50
T;.;.;.
Polyphen
0.12
.;.;B;B
Vest4
0.33
MVP
0.19
MPC
0.097
ClinPred
0.061
T
GERP RS
6.2
Mutation Taster
=81/19
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs373770383; hg19: chr2-179582811; API