rs200217934

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_001267550.2(TTN):​c.65915G>A​(p.Arg21972His) variant causes a missense change. The variant allele was found at a frequency of 0.0000881 in 1,612,496 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 0.000053 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000092 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

1
3
13

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:7

Conservation

PhyloP100: 4.99

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: Likely_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.14927834).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.65915G>A p.Arg21972His missense_variant Exon 314 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.65915G>A p.Arg21972His missense_variant Exon 314 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.0000526
AC:
8
AN:
151966
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000242
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:
0.000103
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000727
AC:
18
AN:
247646
AF XY:
0.0000819
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000581
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000466
Gnomad NFE exome
AF:
0.000116
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000917
AC:
134
AN:
1460530
Hom.:
0
Cov.:
32
AF XY:
0.0000826
AC XY:
60
AN XY:
726548
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33388
American (AMR)
AF:
0.0000672
AC:
3
AN:
44668
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26088
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39586
South Asian (SAS)
AF:
0.0000464
AC:
4
AN:
86176
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53366
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5746
European-Non Finnish (NFE)
AF:
0.000112
AC:
124
AN:
1111196
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60316
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.476
Heterozygous variant carriers
0
7
14
21
28
35
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.0000526
AC:
8
AN:
151966
Hom.:
0
Cov.:
33
AF XY:
0.0000539
AC XY:
4
AN XY:
74198
show subpopulations
African (AFR)
AF:
0.0000242
AC:
1
AN:
41402
American (AMR)
AF:
0.00
AC:
0
AN:
15248
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5142
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000103
AC:
7
AN:
67962
Other (OTH)
AF:
0.00
AC:
0
AN:
2082
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.456
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.000116
Hom.:
0
Bravo
AF:
0.0000604
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000243
AC:
2
ExAC
AF:
0.0000911
AC:
11
EpiCase
AF:
0.00
EpiControl
AF:
0.0000594

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:7
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:4
Feb 16, 2020
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The TTN c.65915G>A; p.Arg21972His variant (rs200217934; ClinVar Variation ID: 264599) is rare in the general population (<1% 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.Arg21972His 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). Herman DS et al. Truncations of titin causing dilated cardiomyopathy. N Engl J Med. 2012 Feb 16;366(7):619-28. -

Mar 07, 2017
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Oct 17, 2023
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mar 17, 2022
Mayo Clinic Laboratories, Mayo Clinic
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

BP4, PM2 -

not specified Uncertain:1
Jun 19, 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.58211G>A (p.Arg19404His) results in a non-conservative amino acid change located in the A-band region of the encoded protein sequence. Two of four in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 7.3e-05 in 247646 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in TTN causing Dilated Cardiomyopathy (0.00039), allowing no conclusion about variant significance. To our knowledge, no occurrence of c.58211G>A in individuals affected with Dilated Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 264599). 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
Aug 24, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Uncertain:1
Dec 14, 2015
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R12907H variant (also known as c.38720G>A), located in coding exon 141 of the TTN gene, results from a G to A substitution at nucleotide position 38720. The arginine at codon 12907 is replaced by histidine, an amino acid with highly similar properties. This variant was previously reported in the SNPDatabase as rs200217934. Based on data from the NHLBI Exome Sequencing Project (ESP), the A allele has an overall frequency of approximately 0.02% (2/11944) total alleles studied and 0.02% (2/8216) European American alleles. Based on data from ExAC, the A allele was reported in 11 of 119438 (0.009%) total alleles (Exome Aggregation Consortium (ExAC), Cambridge, MA (URL: http://exac.broadinstitute.org) [Accessed December 7, 2015]). This amino acid position is well conserved in available vertebrate species; however, histidine is the reference amino acid in one species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.12
BayesDel_addAF
Benign
-0.20
T
BayesDel_noAF
Benign
-0.30
CADD
Uncertain
23
DANN
Benign
0.93
Eigen
Benign
0.028
Eigen_PC
Benign
0.20
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.88
D;D;D;.;D;D;D
M_CAP
Benign
0.017
T
MetaRNN
Benign
0.15
T;T;T;T;T;T;T
MetaSVM
Benign
-0.96
T
MutationAssessor
Benign
1.3
.;.;.;L;.;.;L
PhyloP100
5.0
PrimateAI
Uncertain
0.52
T
PROVEAN
Uncertain
-3.1
D;D;.;.;D;D;.
REVEL
Benign
0.13
Sift
Benign
0.12
T;T;.;.;T;T;.
Polyphen
0.081
.;.;.;B;.;.;B
Vest4
0.36
MVP
0.20
MPC
0.12
ClinPred
0.13
T
GERP RS
5.0
Mutation Taster
=95/5
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: rs200217934; hg19: chr2-179447268; API