rs201418615

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_StrongBP6BS1

The NM_001267550.2(TTN):​c.25481G>A​(p.Arg8494Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000113 in 1,613,692 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 15/19 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 0.00054 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000069 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

2
14

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:8

Conservation

PhyloP100: 2.56

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: Benign. The variant received -9 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.012790918).
BP6
Variant 2-178717253-C-T is Benign according to our data. Variant chr2-178717253-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 192175.
BS1
Variant frequency is greater than expected in population afr. GnomAdExome4 allele frequency = 0.0000691 (101/1461418) while in subpopulation AFR AF = 0.00212 (71/33450). AF 95% confidence interval is 0.00173. There are 1 homozygotes in GnomAdExome4. There are 37 alleles in the male GnomAdExome4 subpopulation. Median coverage is 32. This position passed quality control check.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.25481G>A p.Arg8494Gln missense_variant Exon 88 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.25481G>A p.Arg8494Gln missense_variant Exon 88 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.000539
AC:
82
AN:
152156
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00181
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
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:
0.0000735
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000141
AC:
35
AN:
248936
AF XY:
0.000118
show subpopulations
Gnomad AFR exome
AF:
0.00207
Gnomad AMR exome
AF:
0.0000290
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000887
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000691
AC:
101
AN:
1461418
Hom.:
1
Cov.:
32
AF XY:
0.0000509
AC XY:
37
AN XY:
726988
show subpopulations
African (AFR)
AF:
0.00212
AC:
71
AN:
33450
American (AMR)
AF:
0.0000447
AC:
2
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26124
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39692
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86248
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53392
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.0000189
AC:
21
AN:
1111672
Other (OTH)
AF:
0.0000828
AC:
5
AN:
60356
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.465
Heterozygous variant carriers
0
6
12
18
24
30
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.000539
AC:
82
AN:
152274
Hom.:
0
Cov.:
33
AF XY:
0.000591
AC XY:
44
AN XY:
74444
show subpopulations
African (AFR)
AF:
0.00180
AC:
75
AN:
41574
American (AMR)
AF:
0.000131
AC:
2
AN:
15292
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5174
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4820
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10602
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000735
AC:
5
AN:
68020
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.501
Heterozygous variant carriers
0
4
8
12
16
20
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:
0.000271
Hom.:
0
Bravo
AF:
0.000567
ESP6500AA
AF:
0.00105
AC:
4
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.000132
AC:
16
Asia WGS
AF:
0.000289
AC:
1
AN:
3478
EpiCase
AF:
0.000109
EpiControl
AF:
0.00

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:8
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:5
Aug 29, 2014
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jun 24, 2013
Biesecker Lab/Clinical Genomics Section, National Institutes of Health
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:research

- -

Aug 17, 2023
Revvity Omics, Revvity
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Oct 07, 2020
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is associated with the following publications: (PMID: 27604489, 23861362) -

-
Clinical Genetics, Academic Medical Center
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

not specified Uncertain:1Benign:2
Aug 24, 2020
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: TTN c.21749G>A (p.Arg7250Gln) results in a conservative amino acid change located in the I-band domain of the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.0002 in 280342 control chromosomes, predominantly at a frequency of 0.0022 within the African or African-American subpopulation in the gnomAD database, including 1 homozygote. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 6 fold of the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Dilated Cardiomyopathy phenotype (0.00039), strongly suggesting that the variant is a benign polymorphism found primarily in populations of African or African-American origin. To our knowledge, no occurrence of c.21749G>A in individuals affected with Dilated Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. One co-occurrence with another pathogenic variant has been internally reported (TTR c.424G>A, p.V142I), providing supporting evidence for a benign role. Three ClinVar submitters (evaluation after 2014) cite the variant as uncertain significance (1x) and likely benign (2x). Based on the evidence outlined above, the variant was classified as likely benign. -

Jul 29, 2015
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Arg7250Gln variant in TTN has not been previously reported in individuals with cardiomyopathy, but has been identified in 0.15% (15/9798) of African chrom osomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org ; dbSNP rs201418615). Computational prediction tools and conservation analysis d o not provide strong support for or against an impact to the protein. In summary , the clinical significance of the p.Arg7250Gln variant is uncertain. -

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

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
Jan 29, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.16
BayesDel_addAF
Benign
-0.42
T
BayesDel_noAF
Benign
-0.38
CADD
Benign
23
DANN
Benign
0.91
Eigen
Uncertain
0.30
Eigen_PC
Uncertain
0.35
FATHMM_MKL
Benign
0.62
D
LIST_S2
Benign
0.85
D;D;.;T
M_CAP
Benign
0.055
D
MetaRNN
Benign
0.013
T;T;T;T
MetaSVM
Benign
-0.68
T
PhyloP100
2.6
PrimateAI
Benign
0.40
T
PROVEAN
Benign
-2.0
N;.;.;.
REVEL
Benign
0.13
Sift
Benign
0.47
T;.;.;.
Polyphen
0.98
.;.;D;D
Vest4
0.32
MVP
0.28
MPC
0.23
ClinPred
0.050
T
GERP RS
5.5
Mutation Taster
=86/14
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: rs201418615; hg19: chr2-179581980; COSMIC: COSV59990243; COSMIC: COSV59990243; API