rs186809500

Variant summary

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

The NM_001267550.2(TTN):​c.57971G>A​(p.Arg19324Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000236 in 1,613,298 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R19324W) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

3
7
7

Clinical Significance

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

Conservation

PhyloP100: 7.85

Publications

2 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=0.06587994).
BP6
Variant 2-178594523-C-T is Benign according to our data. Variant chr2-178594523-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 165949.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.57971G>A p.Arg19324Gln missense_variant Exon 296 of 363 ENST00000589042.5 NP_001254479.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.57971G>A p.Arg19324Gln missense_variant Exon 296 of 363 5 NM_001267550.2 ENSP00000467141.1

Frequencies

GnomAD3 genomes
AF:
0.0000526
AC:
8
AN:
151994
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000724
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000973
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000724
AC:
18
AN:
248630
AF XY:
0.0000667
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000580
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000838
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000205
AC:
30
AN:
1461186
Hom.:
0
Cov.:
33
AF XY:
0.0000151
AC XY:
11
AN XY:
726874
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33450
American (AMR)
AF:
0.0000447
AC:
2
AN:
44696
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26120
East Asian (EAS)
AF:
0.000353
AC:
14
AN:
39634
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86222
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53396
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5758
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1111552
Other (OTH)
AF:
0.000116
AC:
7
AN:
60358
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.430
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:
0.0000526
AC:
8
AN:
152112
Hom.:
0
Cov.:
33
AF XY:
0.0000403
AC XY:
3
AN XY:
74356
show subpopulations
African (AFR)
AF:
0.0000722
AC:
3
AN:
41536
American (AMR)
AF:
0.00
AC:
0
AN:
15264
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.000975
AC:
5
AN:
5126
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4816
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67968
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.463
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.00
Hom.:
0
Bravo
AF:
0.0000453
ExAC
AF:
0.0000662
AC:
8

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
Dec 07, 2020
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jul 16, 2019
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is associated with the following publications: (PMID: 31983221) -

not specified Uncertain:1
Jun 27, 2014
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The Arg16756Gln variant in TTN has not been previously reported in individuals w ith cardiomyopathy, but has been identified in 1/200 Southern Han Chinese chromo somes by the 1000 Genomes Project (dbSNP rs186809500). Computational prediction tools and conservation analysis suggest that this variant may impact the protein , though this information is not predictive enough to determine pathogenicity. I n summary, the clinical significance of the Arg16756Gln variant is uncertain. -

Cardiovascular phenotype Benign:1
Jun 24, 2019
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
Uncertain
0.41
BayesDel_addAF
Benign
-0.25
T
BayesDel_noAF
Benign
-0.22
CADD
Uncertain
24
DANN
Uncertain
0.98
Eigen
Pathogenic
0.90
Eigen_PC
Pathogenic
0.90
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.97
D;D;D;.;D;D;D
M_CAP
Benign
0.0080
T
MetaRNN
Benign
0.066
T;T;T;T;T;T;T
MetaSVM
Benign
-0.39
T
MutationAssessor
Uncertain
2.3
.;.;.;M;.;.;M
PhyloP100
7.8
PrimateAI
Uncertain
0.59
T
PROVEAN
Uncertain
-2.9
D;D;.;.;D;D;.
REVEL
Uncertain
0.52
Sift
Benign
0.062
T;D;.;.;D;D;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.51
MVP
0.35
MPC
0.50
ClinPred
0.34
T
GERP RS
6.0
Mutation Taster
=56/44
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.050
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: rs186809500; hg19: chr2-179459250; COSMIC: COSV100636028; COSMIC: COSV100636028; API