rs72648990

Variant summary

Our verdict is Benign. The variant received -13 ACMG points: 0P and 13B. BP4_StrongBP6BS1BS2

The NM_001267550.2(TTN):​c.26528C>T​(p.Thr8843Met) variant causes a missense change. The variant allele was found at a frequency of 0.000381 in 1,613,490 control chromosomes in the GnomAD database, including 2 homozygotes. 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). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T8843K) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00032 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00039 ( 2 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

1
2
13

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:7B:6

Conservation

PhyloP100: 6.58

Publications

6 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: Benign. The variant received -13 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.065653354).
BP6
Variant 2-178714130-G-A is Benign according to our data. Variant chr2-178714130-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 46782.We mark this variant Benign, oryginal submissions are: {Uncertain_significance=7, Likely_benign=6}.
BS1
Variant frequency is greater than expected in population mid. GnomAdExome4 allele frequency = 0.000388 (567/1461286) while in subpopulation MID AF = 0.00295 (17/5762). AF 95% confidence interval is 0.00188. There are 2 homozygotes in GnomAdExome4. There are 286 alleles in the male GnomAdExome4 subpopulation. Median coverage is 34. This position passed quality control check.
BS2
High Homozygotes in GnomAdExome4 at 2 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.26528C>T p.Thr8843Met missense_variant Exon 92 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.26528C>T p.Thr8843Met missense_variant Exon 92 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.000322
AC:
49
AN:
152086
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000121
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000524
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00633
Gnomad NFE
AF:
0.000426
Gnomad OTH
AF:
0.00240
GnomAD2 exomes
AF:
0.000402
AC:
100
AN:
248552
AF XY:
0.000378
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00108
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000435
Gnomad OTH exome
AF:
0.000831
GnomAD4 exome
AF:
0.000388
AC:
567
AN:
1461286
Hom.:
2
Cov.:
34
AF XY:
0.000393
AC XY:
286
AN XY:
726900
show subpopulations
African (AFR)
AF:
0.000239
AC:
8
AN:
33438
American (AMR)
AF:
0.00103
AC:
46
AN:
44680
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26122
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39692
South Asian (SAS)
AF:
0.000429
AC:
37
AN:
86178
European-Finnish (FIN)
AF:
0.0000375
AC:
2
AN:
53390
Middle Eastern (MID)
AF:
0.00295
AC:
17
AN:
5762
European-Non Finnish (NFE)
AF:
0.000376
AC:
418
AN:
1111672
Other (OTH)
AF:
0.000646
AC:
39
AN:
60352
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.487
Heterozygous variant carriers
0
33
66
98
131
164
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
20
40
60
80
100
<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:
0.000315
AC:
48
AN:
152204
Hom.:
0
Cov.:
33
AF XY:
0.000282
AC XY:
21
AN XY:
74410
show subpopulations
African (AFR)
AF:
0.000120
AC:
5
AN:
41538
American (AMR)
AF:
0.000523
AC:
8
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4814
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10606
Middle Eastern (MID)
AF:
0.00340
AC:
1
AN:
294
European-Non Finnish (NFE)
AF:
0.000426
AC:
29
AN:
68006
Other (OTH)
AF:
0.00237
AC:
5
AN:
2106
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.498
Heterozygous variant carriers
0
3
5
8
10
13
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:
0.000409
Hom.:
0
Bravo
AF:
0.000472
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.000519
AC:
2
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000856
AC:
7
ExAC
AF:
0.000348
AC:
42
EpiCase
AF:
0.000764
EpiControl
AF:
0.000652

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:7Benign:6
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2Benign:4
Jul 03, 2018
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 24, 2021
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The TTN c.26528C>T; p.Thr8843Met variant (rs72648990; ClinVar Variation ID: 46782) 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). Given the available evidence, the clinical significance of the p.Thr8843Met variant cannot be determined with certainty. -

Feb 22, 2021
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is associated with the following publications: (PMID: 24503780, 27066507) -

Jul 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

TTN: BP4 -

Dec 30, 2019
Athena Diagnostics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

May 30, 2023
Revvity Omics, Revvity
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1Benign:2
Jun 28, 2017
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.Thr7599Met va riant in TTN has been identified by our laboratory in 1 Asian adult with HCM, 1 Ethiopian neonate with congenital HCM, and 2 Caucasian adults with DCM, of which 1 carried a likely pathogenic variant in another gene sufficient to explain the ir disease (Pugh 2014). Additionally, this variant has been identified in 0.1% ( 38/34342) of Latino chromosomes by the Genome Aggregation Database (gnomAD, http ://gnomad.broadinstitute.org/; dbSNP rs72648990) and has been reported in ClinVa r (Variation ID: 46782). Threonine (Thr) at position 7599 is not conserved in ma mmals or evolutionarily distant species, and one mammal (white rhinoceros) carri es a methionine (Met) at this position, raising the possibility that this change may be tolerated. Additional computational prediction tools do not provide stro ng support for or against an impact to the protein. In summary, while the clinic al significance of the p.Thr7599Met variant is uncertain, its frequency and lack of conservation suggest that it is more likely to be benign. -

Aug 06, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Apr 09, 2025
Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

TTN-related disorder Uncertain:1
Aug 07, 2018
Genomic Research Center, Shahid Beheshti University of Medical Sciences
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Aug 22, 2017
Labcorp Genetics (formerly Invitae), Labcorp
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
Jan 25, 2023
Department of Pathology and Laboratory Medicine, Sinai Health System
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:research

- -

Hypertrophic cardiomyopathy Uncertain:1
-
Genetics and Genomics Program, Sidra Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:research

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.085
BayesDel_addAF
Benign
-0.47
T
BayesDel_noAF
Benign
-0.50
CADD
Benign
21
DANN
Benign
0.90
Eigen
Benign
0.13
Eigen_PC
Uncertain
0.34
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Benign
0.82
T;T;.;T
M_CAP
Benign
0.034
D
MetaRNN
Benign
0.066
T;T;T;T
MetaSVM
Benign
-1.0
T
PhyloP100
6.6
PrimateAI
Benign
0.32
T
PROVEAN
Uncertain
-2.5
D;.;.;.
REVEL
Benign
0.14
Sift
Benign
0.085
T;.;.;.
Polyphen
0.029
.;.;B;B
Vest4
0.19
MVP
0.30
MPC
0.089
ClinPred
0.047
T
GERP RS
5.9
Mutation Taster
=88/12
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: rs72648990; hg19: chr2-179578857; COSMIC: COSV100597464; COSMIC: COSV100597464; API