rs72646851

Variant summary

Our verdict is Benign. The variant received -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_001267550.2(TTN):​c.63026G>A​(p.Arg21009Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00117 in 1,613,182 control chromosomes in the GnomAD database, including 22 homozygotes. In-silico tool predicts a benign outcome for this variant. 11/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. R21009R) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0065 ( 11 hom., cov: 32)
Exomes 𝑓: 0.00061 ( 11 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

3
4
9

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:18

Conservation

PhyloP100: 7.86

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 -20 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.010492563).
BP6
Variant 2-178588699-C-T is Benign according to our data. Variant chr2-178588699-C-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 47189.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00653 (994/152118) while in subpopulation AFR AF = 0.0226 (939/41526). AF 95% confidence interval is 0.0214. There are 11 homozygotes in GnomAd4. There are 480 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
BS2
High Homozygotes in GnomAd4 at 11 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.63026G>A p.Arg21009Gln missense_variant Exon 304 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.63026G>A p.Arg21009Gln missense_variant Exon 304 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.00654
AC:
994
AN:
152000
Hom.:
11
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0227
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00269
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:
0.000118
Gnomad OTH
AF:
0.00287
GnomAD2 exomes
AF:
0.00161
AC:
401
AN:
248514
AF XY:
0.00122
show subpopulations
Gnomad AFR exome
AF:
0.0239
Gnomad AMR exome
AF:
0.000667
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000444
Gnomad OTH exome
AF:
0.000498
GnomAD4 exome
AF:
0.000608
AC:
888
AN:
1461064
Hom.:
11
Cov.:
32
AF XY:
0.000506
AC XY:
368
AN XY:
726812
show subpopulations
African (AFR)
AF:
0.0220
AC:
735
AN:
33440
American (AMR)
AF:
0.000962
AC:
43
AN:
44698
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26112
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39622
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86212
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53380
Middle Eastern (MID)
AF:
0.000174
AC:
1
AN:
5758
European-Non Finnish (NFE)
AF:
0.0000405
AC:
45
AN:
1111492
Other (OTH)
AF:
0.00106
AC:
64
AN:
60350
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.469
Heterozygous variant carriers
0
55
110
165
220
275
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
24
48
72
96
120
<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:
0.00653
AC:
994
AN:
152118
Hom.:
11
Cov.:
32
AF XY:
0.00645
AC XY:
480
AN XY:
74366
show subpopulations
African (AFR)
AF:
0.0226
AC:
939
AN:
41526
American (AMR)
AF:
0.00269
AC:
41
AN:
15262
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5136
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000118
AC:
8
AN:
67972
Other (OTH)
AF:
0.00284
AC:
6
AN:
2110
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.505
Heterozygous variant carriers
0
46
92
138
184
230
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
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
Alfa
AF:
0.00244
Hom.:
9
Bravo
AF:
0.00695
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.00
AC:
0
ESP6500AA
AF:
0.0220
AC:
84
ESP6500EA
AF:
0.000242
AC:
2
ExAC
AF:
0.00194
AC:
235
Asia WGS
AF:
0.000578
AC:
2
AN:
3476
EpiCase
AF:
0.0000546
EpiControl
AF:
0.00

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:18
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:10
Jul 09, 2014
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

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

- -

May 10, 2020
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Aug 15, 2012
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Arg18441Gln in Exon 253 of TTN: This variant is not expected to have clinical si gnificance because it has been identified in 2.2% (68/3122) of African American chromosomes from a broad population by the NHLBI Exome Sequencing Project (http: //evs.gs.washington.edu/EVS; dbSNP rs72646851). -

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

- -

-
Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

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

- -

-
Genome Diagnostics Laboratory, University Medical Center Utrecht
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Jul 31, 2024
Athena Diagnostics
Significance: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:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J Benign:1
Sep 10, 2021
Genome-Nilou Lab
Significance: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 30, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiomyopathy Benign:1
Jan 09, 2023
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Early-onset myopathy with fatal cardiomyopathy Benign:1
Sep 10, 2021
Genome-Nilou Lab
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Tibial muscular dystrophy Benign:1
Sep 10, 2021
Genome-Nilou Lab
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Myopathy, myofibrillar, 9, with early respiratory failure Benign:1
Sep 10, 2021
Genome-Nilou Lab
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Heart failure;C0023976:Long QT syndrome;C0878544:Cardiomyopathy Benign:1
Jun 03, 2019
Center for Advanced Laboratory Medicine, UC San Diego Health, University of California San Diego
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Benign:1
Sep 28, 2017
Ambry Genetics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

General population or subpopulation frequency is too high to be a pathogenic mutation based on disease/syndrome prevalence and penetrance -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.24
BayesDel_addAF
Benign
-0.39
T
BayesDel_noAF
Benign
-0.32
CADD
Benign
21
DANN
Benign
0.97
Eigen
Pathogenic
0.82
Eigen_PC
Pathogenic
0.85
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.95
D;D;D;.;D;D;D
MetaRNN
Benign
0.010
T;T;T;T;T;T;T
MetaSVM
Benign
-0.66
T
MutationAssessor
Benign
1.9
.;.;.;L;.;.;L
PhyloP100
7.9
PrimateAI
Benign
0.45
T
PROVEAN
Uncertain
-2.9
D;D;.;.;D;D;.
REVEL
Uncertain
0.30
Sift
Uncertain
0.011
D;D;.;.;D;D;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.41
MVP
0.28
MPC
0.50
ClinPred
0.018
T
GERP RS
6.2
Mutation Taster
=98/2
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: rs72646851; hg19: chr2-179453426; COSMIC: COSV105216549; COSMIC: COSV105216549; API