rs55861600

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.79318C>T​(p.Arg26440Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00147 in 1,613,184 control chromosomes in the GnomAD database, including 29 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R26440H) has been classified as Benign.

Frequency

Genomes: 𝑓 0.0075 ( 16 hom., cov: 33)
Exomes 𝑓: 0.00084 ( 13 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

1
7
8

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:26

Conservation

PhyloP100: 3.41

Publications

7 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=0.007461846).
BP6
Variant 2-178566814-G-A is Benign according to our data. Variant chr2-178566814-G-A is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 47374.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 = 0.00751 (1143/152110) while in subpopulation AFR AF = 0.026 (1078/41508). AF 95% confidence interval is 0.0247. There are 16 homozygotes in GnomAd4. There are 525 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.
BS2
High Homozygotes in GnomAd4 at 16 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.79318C>T p.Arg26440Cys missense_variant Exon 326 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.79318C>T p.Arg26440Cys missense_variant Exon 326 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.00751
AC:
1142
AN:
151992
Hom.:
16
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0260
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00262
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000415
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00316
Gnomad NFE
AF:
0.000147
Gnomad OTH
AF:
0.00621
GnomAD2 exomes
AF:
0.00196
AC:
487
AN:
248008
AF XY:
0.00140
show subpopulations
Gnomad AFR exome
AF:
0.0271
Gnomad AMR exome
AF:
0.00136
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000713
Gnomad OTH exome
AF:
0.000830
GnomAD4 exome
AF:
0.000842
AC:
1230
AN:
1461074
Hom.:
13
Cov.:
38
AF XY:
0.000743
AC XY:
540
AN XY:
726852
show subpopulations
African (AFR)
AF:
0.0281
AC:
940
AN:
33450
American (AMR)
AF:
0.00150
AC:
67
AN:
44700
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26126
East Asian (EAS)
AF:
0.0000505
AC:
2
AN:
39622
South Asian (SAS)
AF:
0.000209
AC:
18
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53154
Middle Eastern (MID)
AF:
0.00104
AC:
6
AN:
5764
European-Non Finnish (NFE)
AF:
0.0000711
AC:
79
AN:
1111660
Other (OTH)
AF:
0.00196
AC:
118
AN:
60346
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.474
Heterozygous variant carriers
0
83
166
250
333
416
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
32
64
96
128
160
<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:
0.00751
AC:
1143
AN:
152110
Hom.:
16
Cov.:
33
AF XY:
0.00706
AC XY:
525
AN XY:
74340
show subpopulations
African (AFR)
AF:
0.0260
AC:
1078
AN:
41508
American (AMR)
AF:
0.00262
AC:
40
AN:
15264
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5150
South Asian (SAS)
AF:
0.000208
AC:
1
AN:
4816
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10608
Middle Eastern (MID)
AF:
0.00340
AC:
1
AN:
294
European-Non Finnish (NFE)
AF:
0.000147
AC:
10
AN:
67974
Other (OTH)
AF:
0.00614
AC:
13
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.502
Heterozygous variant carriers
0
57
114
171
228
285
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
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
Alfa
AF:
0.00296
Hom.:
28
Bravo
AF:
0.00909
ESP6500AA
AF:
0.0265
AC:
99
ESP6500EA
AF:
0.000122
AC:
1
ExAC
AF:
0.00231
AC:
279
Asia WGS
AF:
0.00115
AC:
4
AN:
3478
EpiCase
AF:
0.0000546
EpiControl
AF:
0.0000593

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:26
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:10
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

- -

Jul 26, 2013
Eurofins Ntd Llc (ga)
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 09, 2012
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Arg23872Cys in exon 275 of TTN: This variant is not expected to have clinical si gnificance because it is not located within the splice consensus sequence and ha s been identified in 0.7% (16/2286) of racially unspecified chromosomes (dbSNP r s55861600) and in 2.5% (76/3036) of African American chromosomes (NHLBI Exome Se quencing Project; http://evs.gs.washington.edu/EVS) from two broad, though clini cally unspecified populations. -

Apr 17, 2013
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

- -

Mar 30, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely benign
Review Status:criteria provided, single submitter
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

- -

Nov 09, 2020
Athena Diagnostics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
PreventionGenetics, part of Exact Sciences
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

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

- -

not provided Benign:4
-
Breakthrough Genomics, Breakthrough Genomics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:not provided

- -

-
Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

-
Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Jul 29, 2024
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J Benign:2
Sep 10, 2021
Genome-Nilou Lab
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Early-onset myopathy with fatal cardiomyopathy Benign:2
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

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:2
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

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

- -

Tibial muscular dystrophy Benign:2
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

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 31, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiomyopathy Benign:1
Sep 13, 2017
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dilated cardiomyopathy 1G Benign:1
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Cardiovascular phenotype Benign:1
Sep 18, 2013
Ambry Genetics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as benign based on a combination of the following: 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
Benign
0.18
BayesDel_addAF
Benign
-0.35
T
BayesDel_noAF
Benign
-0.26
CADD
Benign
23
DANN
Benign
0.88
Eigen
Uncertain
0.54
Eigen_PC
Uncertain
0.53
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Uncertain
0.94
D;D;D;.;D;D;D
MetaRNN
Benign
0.0075
T;T;T;T;T;T;T
MetaSVM
Benign
-0.67
T
MutationAssessor
Benign
1.9
.;.;.;M;.;.;M
PhyloP100
3.4
PrimateAI
Uncertain
0.71
T
PROVEAN
Pathogenic
-5.3
D;D;.;.;D;D;.
REVEL
Uncertain
0.33
Sift
Uncertain
0.0060
D;D;.;.;D;D;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.46
MVP
0.55
MPC
0.46
ClinPred
0.045
T
GERP RS
4.9
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: rs55861600; hg19: chr2-179431541; COSMIC: COSV60127656; API