rs200471370

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_ModerateBP6BS2

The NM_001267550.2(TTN):​c.72182T>C​(p.Met24061Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000292 in 1,613,094 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts 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. M24061V) has been classified as Likely benign.

Frequency

Genomes: š‘“ 0.00013 ( 0 hom., cov: 33)
Exomes š‘“: 0.00031 ( 2 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

1
5
11

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:2

Conservation

PhyloP100: 9.27

Publications

4 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 -7 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.22391528).
BP6
Variant 2-178573950-A-G is Benign according to our data. Variant chr2-178573950-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 47313.
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.72182T>C p.Met24061Thr missense_variant Exon 326 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.72182T>C p.Met24061Thr missense_variant Exon 326 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.000132
AC:
20
AN:
151940
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000483
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:
0.000250
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.000137
AC:
34
AN:
248154
AF XY:
0.000126
show subpopulations
Gnomad AFR exome
AF:
0.000259
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:
0.000267
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000309
AC:
451
AN:
1461154
Hom.:
2
Cov.:
38
AF XY:
0.000299
AC XY:
217
AN XY:
726876
show subpopulations
African (AFR)
AF:
0.0000897
AC:
3
AN:
33452
American (AMR)
AF:
0.0000224
AC:
1
AN:
44704
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26124
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39554
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86240
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53376
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.000345
AC:
384
AN:
1111590
Other (OTH)
AF:
0.00104
AC:
63
AN:
60350
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.491
Heterozygous variant carriers
0
28
55
83
110
138
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:
0.000132
AC:
20
AN:
151940
Hom.:
0
Cov.:
33
AF XY:
0.0000943
AC XY:
7
AN XY:
74200
show subpopulations
African (AFR)
AF:
0.0000483
AC:
2
AN:
41372
American (AMR)
AF:
0.00
AC:
0
AN:
15254
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5148
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4818
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10592
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000250
AC:
17
AN:
67972
Other (OTH)
AF:
0.000478
AC:
1
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.478
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:
0.000249
Hom.:
0
Bravo
AF:
0.000147
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000609
AC:
5
ExAC
AF:
0.000116
AC:
14
EpiCase
AF:
0.000437
EpiControl
AF:
0.000297

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:5Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2Benign:1
Jun 04, 2014
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Sep 23, 2022
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 15, 2021
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is associated with the following publications: (PMID: 27193218, 24503780) -

not specified Uncertain:2
Jan 04, 2012
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 Met21493Thr var iant (TTN) has not been previously reported in the literature, but has been dete cted in 1 Caucasian individual with DCM tested by our laboratory and did not seg regate with disease in 1 affected relative. This variant has been identified in 5/6610 European American chromosomes from a broad, though clinically unspecified population (NHLBI Exome Sequencing Project; http://evs.gs.washington.edu/EVS). Methionine (Met) at position 21493 is conserved in mammals, but not in more dist antly related species, suggesting that a change may be tolerated. Computational predictions are mixed regarding the possible impact to the protein (AlignGVGD = benign, SIFT = pathogenic), though the accuracy of these tools is unknown. Altho ugh this data suggests that the Met21493Thr variant may be benign, additional in formation is needed to fully assess its clinical significance. -

Oct 11, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: TTN c.64478T>C (p.Met21493Thr), also reported as NM_001267550:c.72182T>C (p.Met24061Thr), results in a non-conservative amino acid change located in the A-band region of the encoded protein sequence. Two of three in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00029 in 1613094 control chromosomes in the gnomAD database, including 2 homozygotes. This frequency is not significantly higher than estimated for a pathogenic variant in TTN causing recessive disease, allowing no conclusion about variant significance. c.64478T>C has been reported in the literature in individuals affected with dilated cardiomyopathy with atrial fibrillation (example, Pugh_2014). These report(s) do not provide unequivocal conclusions about association of the variant with TTN-related conditions. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 24503780). ClinVar contains an entry for this variant (Variation ID: 47313). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Jul 11, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Benign:1
May 21, 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
0.33
BayesDel_addAF
Benign
-0.19
T
BayesDel_noAF
Benign
-0.22
CADD
Benign
20
DANN
Benign
0.88
Eigen
Uncertain
0.21
Eigen_PC
Uncertain
0.42
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Benign
0.80
T;T;T;.;T;T;T
M_CAP
Benign
0.031
D
MetaRNN
Benign
0.22
T;T;T;T;T;T;T
MetaSVM
Benign
-0.77
T
MutationAssessor
Benign
0.40
.;.;.;N;.;.;N
PhyloP100
9.3
PrimateAI
Uncertain
0.56
T
PROVEAN
Uncertain
-4.0
D;D;.;.;D;D;.
REVEL
Uncertain
0.40
Sift
Benign
0.22
T;T;.;.;T;T;.
Polyphen
0.42
.;.;.;B;.;.;B
Vest4
0.40
MVP
0.73
MPC
0.14
ClinPred
0.30
T
GERP RS
6.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Mutation Taster
=84/16
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: rs200471370; hg19: chr2-179438677; API