rs397517827

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_StrongBP6BS2

The NM_001267550.2(TTN):​c.11842C>T​(p.Arg3948Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000132 in 1,613,870 control chromosomes in the GnomAD database, including 3 homozygotes. In-silico tool predicts a benign outcome for this variant. 16/19 in silico tools predict 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. R3948L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00011 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00013 ( 3 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

16

Clinical Significance

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

Conservation

PhyloP100: 1.41

Publications

8 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=0.046164513).
BP6
Variant 2-178741391-G-A is Benign according to our data. Variant chr2-178741391-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 47813.
BS2
High Homozygotes in GnomAdExome4 at 3 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.11842C>T p.Arg3948Cys missense_variant Exon 48 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.11842C>T p.Arg3948Cys missense_variant Exon 48 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.000118
AC:
18
AN:
152138
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000966
Gnomad SAS
AF:
0.00228
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000205
AC:
51
AN:
248520
AF XY:
0.000282
show subpopulations
Gnomad AFR exome
AF:
0.000129
Gnomad AMR exome
AF:
0.0000290
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000724
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000267
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000134
AC:
196
AN:
1461614
Hom.:
3
Cov.:
32
AF XY:
0.000195
AC XY:
142
AN XY:
727090
show subpopulations
African (AFR)
AF:
0.0000896
AC:
3
AN:
33472
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.000378
AC:
15
AN:
39696
South Asian (SAS)
AF:
0.00144
AC:
124
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53394
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000405
AC:
45
AN:
1111816
Other (OTH)
AF:
0.000133
AC:
8
AN:
60366
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.498
Heterozygous variant carriers
0
15
29
44
58
73
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
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:
0.000112
AC:
17
AN:
152256
Hom.:
0
Cov.:
32
AF XY:
0.000148
AC XY:
11
AN XY:
74436
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41566
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.000968
AC:
5
AN:
5166
South Asian (SAS)
AF:
0.00207
AC:
10
AN:
4824
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:
0.0000147
AC:
1
AN:
68014
Other (OTH)
AF:
0.00
AC:
0
AN:
2108
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.483
Heterozygous variant carriers
0
1
3
4
6
7
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:
0.0000580
Hom.:
0
Bravo
AF:
0.0000680
ExAC
AF:
0.000215
AC:
26
Asia WGS
AF:
0.000577
AC:
2
AN:
3478

ClinVar

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

Submissions by phenotype

not specified Uncertain:1Benign:1
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

- -

May 17, 2012
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The Arg3710Cys variant in TTN has not been reported in the literature nor previo usly identified by our laboratory. It was also absent from a very large and broa d population sequenced by the NHLBI Exome Sequencing Project (http://evs.gs.wash ington.edu/EVS). This low frequency is consistent with a disease causing role bu t insufficient to establish this with confidence. Evolutionary conservation and computational tools are limited or unavailable for this variant. Additional info rmation is needed to fully assess the clinical significance of the Arg3710Cys va riant. -

not provided Uncertain:1Benign:1
Oct 15, 2018
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jul 25, 2024
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The TTN c.11842C>T; p.Arg3948Cys variant (rs397517827; ClinVar Variation ID: 47813) is rare in the general population (<0.2% 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.Arg3948Cys 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). PMID: 26567375. Herman DS et al. Truncations of titin causing dilated cardiomyopathy. N Engl J Med. 2012 Feb 16;366(7):619-28. PMID: 22335739. Linke WA and Hamdani N. Gigantic business: titin properties and function through thick and thin. Circ Res 2014; 114(6): 1052-1068. PMID: 24625729. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.070
BayesDel_addAF
Benign
-0.47
T
BayesDel_noAF
Benign
-0.50
CADD
Benign
14
DANN
Benign
0.48
Eigen
Benign
-0.25
Eigen_PC
Benign
-0.40
FATHMM_MKL
Benign
0.21
N
LIST_S2
Benign
0.67
T;T;.;T;T;T
M_CAP
Benign
0.065
D
MetaRNN
Benign
0.046
T;T;T;T;T;T
MetaSVM
Benign
-0.63
T
PhyloP100
1.4
PrimateAI
Benign
0.21
T
PROVEAN
Benign
-1.8
N;.;.;N;N;.
REVEL
Benign
0.21
Sift
Benign
0.18
T;.;.;T;T;.
Vest4
0.040
MutPred
0.53
.;.;.;.;Gain of methylation at K3774 (P = 0.0475);.;
MVP
0.56
MPC
0.28
ClinPred
0.033
T
GERP RS
4.1
Mutation Taster
=82/18
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: rs397517827; hg19: chr2-179606118; COSMIC: COSV59958604; COSMIC: COSV59958604; API