NM_001267550.2:c.46928A>G

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6

The NM_001267550.2(TTN):​c.46928A>G​(p.His15643Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000273 in 1,612,292 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). Synonymous variant affecting the same amino acid position (i.e. H15643H) has been classified as Likely benign.

Frequency

Genomes: š‘“ 0.00024 ( 0 hom., cov: 33)
Exomes š‘“: 0.00028 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

5
5
8

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:4

Conservation

PhyloP100: 7.56

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 -3 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.079236776).
BP6
Variant 2-178618622-T-C is Benign according to our data. Variant chr2-178618622-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 178209.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.46928A>G p.His15643Arg missense_variant Exon 251 of 363 ENST00000589042.5 NP_001254479.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.46928A>G p.His15643Arg missense_variant Exon 251 of 363 5 NM_001267550.2 ENSP00000467141.1

Frequencies

GnomAD3 genomes
AF:
0.000237
AC:
36
AN:
151960
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000724
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000459
Gnomad ASJ
AF:
0.00173
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000295
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000222
AC:
55
AN:
247944
AF XY:
0.000282
show subpopulations
Gnomad AFR exome
AF:
0.000194
Gnomad AMR exome
AF:
0.000349
Gnomad ASJ exome
AF:
0.00130
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000223
Gnomad OTH exome
AF:
0.000332
GnomAD4 exome
AF:
0.000277
AC:
404
AN:
1460214
Hom.:
0
Cov.:
32
AF XY:
0.000295
AC XY:
214
AN XY:
726384
show subpopulations
African (AFR)
AF:
0.000150
AC:
5
AN:
33350
American (AMR)
AF:
0.000336
AC:
15
AN:
44614
Ashkenazi Jewish (ASJ)
AF:
0.00123
AC:
32
AN:
26080
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39628
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86042
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53348
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5750
European-Non Finnish (NFE)
AF:
0.000287
AC:
319
AN:
1111118
Other (OTH)
AF:
0.000547
AC:
33
AN:
60284
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.471
Heterozygous variant carriers
0
26
51
77
102
128
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
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:
0.000237
AC:
36
AN:
152078
Hom.:
0
Cov.:
33
AF XY:
0.000242
AC XY:
18
AN XY:
74342
show subpopulations
African (AFR)
AF:
0.0000722
AC:
3
AN:
41552
American (AMR)
AF:
0.000459
AC:
7
AN:
15260
Ashkenazi Jewish (ASJ)
AF:
0.00173
AC:
6
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5126
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000295
AC:
20
AN:
67900
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.492
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

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:
0.000447
Hom.:
0
Bravo
AF:
0.000264
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.000778
AC:
3
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000123
AC:
1
ExAC
AF:
0.000108
AC:
13
EpiCase
AF:
0.000164
EpiControl
AF:
0.000356

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:5Benign:4
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:3Benign:1
Nov 09, 2023
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Apr 12, 2021
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is associated with the following publications: (PMID: 23396983)

Jun 30, 2023
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Sep 01, 2022
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

not specified Uncertain:1Benign:1
May 20, 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.His13075Arg variant in TTN has been identified by our laboratory in 1 Cauc asian adult with possible ARVC and a family history of cardiomyopathy and sudden death, who carried a likely pathogenic variant in another gene. This variant ha s also been identified in 10/66616 European chromosomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; dbSNP rs368502650). Computati onal prediction tools and conservation analysis suggest that this variant may im pact the protein, though this information is not predictive enough to determine pathogenicity. In summary, the clinical significance of the p.His13075Arg varian t is uncertain.

Jul 09, 2025
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.39224A>G (p.His13075Arg) results in a non-conservative amino acid change in the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change. The variant allele was found at a frequency of 0.00027 in 1612292 control chromosomes, predominantly at a frequency of 0.0013 within the Ashkenazi Jewish subpopulation in the gnomAD database. The observed variant frequency within Ashkenazi Jewish control individuals in the gnomAD database is approximately 3-fold of the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Dilated Cardiomyopathy phenotype (0.00039). c.39224A>G has been observed in at least one individual affected with Hypertrophic Cardiomyopathy, without strong evidence for causality (e.g. Lopes_2013). This report does not provide unequivocal conclusions about association of the variant with Dilated Cardiomyopathy. 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: 23396983). ClinVar contains an entry for this variant (Variation ID: 178209). Based on the evidence outlined above, the variant was classified as likely benign.

TTN-related disorder Uncertain:1
Aug 26, 2022
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The TTN c.46928A>G variant is predicted to result in the amino acid substitution p.His15643Arg. This variant was reported in an individual with hypertrophic cardiomyopathy (described as p.His6578Arg with an alternate transcript NM_003319 in Table S1, Lopes et al. 2013. PubMed ID: 23396983). This variant is reported in 0.13% of alleles in individuals of Ashkenazi Jewish descent in gnomAD (http://gnomad.broadinstitute.org/variant/2-179483349-T-C). Although we suspect that this variant may be benign, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence.

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
Jan 30, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Cardiovascular phenotype Benign:1
Jun 08, 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
Uncertain
0.38
BayesDel_addAF
Benign
-0.18
T
BayesDel_noAF
Benign
-0.19
CADD
Benign
20
DANN
Benign
0.91
DEOGEN2
Benign
0.0
.;.;.;.;.;.;.
Eigen
Pathogenic
0.73
Eigen_PC
Pathogenic
0.75
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.87
D;D;D;.;D;D;D
M_CAP
Benign
0.038
D
MetaRNN
Benign
0.079
T;T;T;T;T;T;T
MetaSVM
Uncertain
-0.19
T
MutationAssessor
Benign
0.0
.;.;.;M;.;.;M
PhyloP100
7.6
PrimateAI
Uncertain
0.73
T
PROVEAN
Pathogenic
-5.5
D;D;.;.;D;D;.
REVEL
Uncertain
0.51
Sift
Benign
0.066
T;T;.;.;T;T;.
Sift4G
Pathogenic
0.0
.;.;.;.;.;.;.
Vest4
0.45
ClinPred
0.23
T
GERP RS
5.8
Mutation Taster
=59/41
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: rs368502650; hg19: chr2-179483349; COSMIC: COSV60096327; COSMIC: COSV60096327; API