2-178579562-A-G

Variant summary

Our verdict is Benign. The variant received -19 ACMG points: 0P and 19B. BP4_ModerateBP6_Very_StrongBP7BA1

The NM_001256850.1(TTN):​c.62712T>C​(p.Val20904Val) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0251 in 1,612,998 control chromosomes in the GnomAD database, including 632 homozygotes. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.022 ( 60 hom., cov: 32)
Exomes 𝑓: 0.025 ( 572 hom. )

Consequence

TTN
NM_001256850.1 splice_region, synonymous

Scores

2
Splicing: ADA: 0.00007531
2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:24

Conservation

PhyloP100: 1.03
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 -19 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.45).
BP6
Variant 2-178579562-A-G is Benign according to our data. Variant chr2-178579562-A-G is described in ClinVar as [Likely_benign]. Clinvar id is 47255.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178579562-A-G is described in Lovd as [Benign]. Variant chr2-178579562-A-G is described in Lovd as [Likely_benign].
BP7
Synonymous conserved (PhyloP=1.03 with no splicing effect.
BA1
GnomAd4 highest subpopulation (EAS) allele frequency at 95% confidence interval = 0.0559 is higher than 0.05.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.67635T>C p.Val22545Val synonymous_variant Exon 319 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.67635T>C p.Val22545Val synonymous_variant Exon 319 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.0221
AC:
3352
AN:
152002
Hom.:
59
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00468
Gnomad AMI
AF:
0.0307
Gnomad AMR
AF:
0.0237
Gnomad ASJ
AF:
0.0199
Gnomad EAS
AF:
0.0614
Gnomad SAS
AF:
0.0317
Gnomad FIN
AF:
0.0450
Gnomad MID
AF:
0.00633
Gnomad NFE
AF:
0.0251
Gnomad OTH
AF:
0.0215
GnomAD2 exomes
AF:
0.0299
AC:
7379
AN:
247152
AF XY:
0.0294
show subpopulations
Gnomad AFR exome
AF:
0.00511
Gnomad AMR exome
AF:
0.0346
Gnomad ASJ exome
AF:
0.0152
Gnomad EAS exome
AF:
0.0618
Gnomad FIN exome
AF:
0.0478
Gnomad NFE exome
AF:
0.0251
Gnomad OTH exome
AF:
0.0295
GnomAD4 exome
AF:
0.0254
AC:
37164
AN:
1460878
Hom.:
572
Cov.:
34
AF XY:
0.0257
AC XY:
18652
AN XY:
726722
show subpopulations
African (AFR)
AF:
0.00449
AC:
150
AN:
33430
American (AMR)
AF:
0.0327
AC:
1460
AN:
44704
Ashkenazi Jewish (ASJ)
AF:
0.0152
AC:
398
AN:
26112
East Asian (EAS)
AF:
0.0636
AC:
2522
AN:
39662
South Asian (SAS)
AF:
0.0279
AC:
2405
AN:
86230
European-Finnish (FIN)
AF:
0.0492
AC:
2619
AN:
53178
Middle Eastern (MID)
AF:
0.0143
AC:
82
AN:
5754
European-Non Finnish (NFE)
AF:
0.0234
AC:
26034
AN:
1111466
Other (OTH)
AF:
0.0248
AC:
1494
AN:
60342
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.486
Heterozygous variant carriers
0
2160
4320
6479
8639
10799
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
1028
2056
3084
4112
5140
<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:
0.0220
AC:
3352
AN:
152120
Hom.:
60
Cov.:
32
AF XY:
0.0228
AC XY:
1694
AN XY:
74342
show subpopulations
African (AFR)
AF:
0.00467
AC:
194
AN:
41554
American (AMR)
AF:
0.0237
AC:
361
AN:
15256
Ashkenazi Jewish (ASJ)
AF:
0.0199
AC:
69
AN:
3472
East Asian (EAS)
AF:
0.0615
AC:
316
AN:
5136
South Asian (SAS)
AF:
0.0317
AC:
153
AN:
4828
European-Finnish (FIN)
AF:
0.0450
AC:
477
AN:
10604
Middle Eastern (MID)
AF:
0.00680
AC:
2
AN:
294
European-Non Finnish (NFE)
AF:
0.0251
AC:
1707
AN:
67950
Other (OTH)
AF:
0.0213
AC:
45
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.501
Heterozygous variant carriers
0
168
337
505
674
842
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
42
84
126
168
210
<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:
0.0241
Hom.:
233
Bravo
AF:
0.0196
Asia WGS
AF:
0.0410
AC:
143
AN:
3476
EpiCase
AF:
0.0230
EpiControl
AF:
0.0244

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:24
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:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Apr 19, 2012
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

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

- -

Apr 29, 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. -

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

- -

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

- -

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

- -

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

- -

Jan 06, 2020
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Aug 15, 2013
Genetic Services Laboratory, University of Chicago
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Benign:3
Dec 18, 2018
Athena Diagnostics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

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

- -

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

- -

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 13, 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. -

Early-onset myopathy with fatal cardiomyopathy Benign:2
Sep 10, 2021
Genome-Nilou Lab
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 13, 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. -

Tibial muscular dystrophy Benign:2
Sep 10, 2021
Genome-Nilou Lab
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 13, 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. -

Myopathy, myofibrillar, 9, with early respiratory failure Benign:2
Sep 10, 2021
Genome-Nilou Lab
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 13, 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. -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
Feb 04, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dilated cardiomyopathy 1G Benign:1
Jan 13, 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
Mar 06, 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
BayesDel_noAF
Benign
-0.45
CADD
Benign
9.7
DANN
Benign
0.68
PhyloP100
1.0
Mutation Taster
=65/35
polymorphism (auto)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.000075
dbscSNV1_RF
Benign
0.016
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

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Other links and lift over

dbSNP: rs2288570; hg19: chr2-179444289; API