chr2-178548239-G-A

Variant summary

Our verdict is Benign. The variant received -19 ACMG points: 0P and 19B. BP4_ModerateBP6_Very_StrongBP7BS1BS2

The NM_001267550.2(TTN):​c.93387C>T​(p.Ser31129Ser) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0246 in 1,613,804 control chromosomes in the GnomAD database, including 631 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.021 ( 76 hom., cov: 32)
Exomes 𝑓: 0.025 ( 555 hom. )

Consequence

TTN
NM_001267550.2 synonymous

Scores

2

Clinical Significance

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

Conservation

PhyloP100: 0.0990

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 -19 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.38).
BP6
Variant 2-178548239-G-A is Benign according to our data. Variant chr2-178548239-G-A is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 47532.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BP7
Synonymous conserved (PhyloP=0.099 with no splicing effect.
BS1
Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.0208 (3159/152216) while in subpopulation NFE AF = 0.0304 (2066/68004). AF 95% confidence interval is 0.0293. There are 76 homozygotes in GnomAd4. There are 1491 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
BS2
High Homozygotes in GnomAd4 at 76 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.93387C>T p.Ser31129Ser synonymous_variant Exon 339 of 363 ENST00000589042.5 NP_001254479.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.93387C>T p.Ser31129Ser synonymous_variant Exon 339 of 363 5 NM_001267550.2 ENSP00000467141.1

Frequencies

GnomAD3 genomes
AF:
0.0208
AC:
3157
AN:
152098
Hom.:
76
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00459
Gnomad AMI
AF:
0.270
Gnomad AMR
AF:
0.0169
Gnomad ASJ
AF:
0.0138
Gnomad EAS
AF:
0.000193
Gnomad SAS
AF:
0.00353
Gnomad FIN
AF:
0.0271
Gnomad MID
AF:
0.0158
Gnomad NFE
AF:
0.0304
Gnomad OTH
AF:
0.0187
GnomAD2 exomes
AF:
0.0200
AC:
4967
AN:
248470
AF XY:
0.0202
show subpopulations
Gnomad AFR exome
AF:
0.00381
Gnomad AMR exome
AF:
0.0124
Gnomad ASJ exome
AF:
0.00996
Gnomad EAS exome
AF:
0.000111
Gnomad FIN exome
AF:
0.0287
Gnomad NFE exome
AF:
0.0311
Gnomad OTH exome
AF:
0.0226
GnomAD4 exome
AF:
0.0250
AC:
36539
AN:
1461588
Hom.:
555
Cov.:
34
AF XY:
0.0245
AC XY:
17795
AN XY:
727074
show subpopulations
African (AFR)
AF:
0.00400
AC:
134
AN:
33470
American (AMR)
AF:
0.0137
AC:
611
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.0111
AC:
289
AN:
26132
East Asian (EAS)
AF:
0.0000756
AC:
3
AN:
39694
South Asian (SAS)
AF:
0.00463
AC:
399
AN:
86258
European-Finnish (FIN)
AF:
0.0278
AC:
1485
AN:
53388
Middle Eastern (MID)
AF:
0.0161
AC:
93
AN:
5766
European-Non Finnish (NFE)
AF:
0.0290
AC:
32274
AN:
1111792
Other (OTH)
AF:
0.0207
AC:
1251
AN:
60370
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.481
Heterozygous variant carriers
0
2509
5018
7527
10036
12545
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
1162
2324
3486
4648
5810
<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:
0.0208
AC:
3159
AN:
152216
Hom.:
76
Cov.:
32
AF XY:
0.0200
AC XY:
1491
AN XY:
74418
show subpopulations
African (AFR)
AF:
0.00460
AC:
191
AN:
41556
American (AMR)
AF:
0.0168
AC:
257
AN:
15270
Ashkenazi Jewish (ASJ)
AF:
0.0138
AC:
48
AN:
3470
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5168
South Asian (SAS)
AF:
0.00353
AC:
17
AN:
4818
European-Finnish (FIN)
AF:
0.0271
AC:
288
AN:
10612
Middle Eastern (MID)
AF:
0.0170
AC:
5
AN:
294
European-Non Finnish (NFE)
AF:
0.0304
AC:
2066
AN:
68004
Other (OTH)
AF:
0.0189
AC:
40
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
156
311
467
622
778
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
38
76
114
152
190
<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:
0.0242
Hom.:
34
Bravo
AF:
0.0204
Asia WGS
AF:
0.00346
AC:
12
AN:
3478
EpiCase
AF:
0.0285
EpiControl
AF:
0.0314

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:24
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:8
-
PreventionGenetics, part of Exact Sciences
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

- -

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

- -

Nov 11, 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. -

Nov 06, 2019
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: TTN c.85683C>T alters a non-conserved nucleotide resulting in a synonymous change. 5/5 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.02 in 248470 control chromosomes, predominantly at a frequency of 0.031 within the Non-Finnish European subpopulation in the gnomAD database, including 55 homozygotes. The observed variant frequency within Non-Finnish European control individuals in the gnomAD database is approximately 50-folds over the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Cardiomyopathy phenotype (0.00063), strongly suggesting that the variant is a benign polymorphism found primarily in populations of Non-Finnish European origin. To our knowledge, no occurrence of c.85683C>T in individuals affected with Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. Two ClinVar submissions (evaluation after 2014) cite the variant once as likely benign and once as benign. Based on the evidence outlined above, the variant was classified as benign. -

Aug 15, 2013
Genetic Services Laboratory, University of Chicago
Significance: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

- -

not provided Benign:5
Oct 02, 2023
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

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

- -

Feb 26, 2019
Athena Diagnostics
Significance:Benign
Review Status:criteria provided, single submitter
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

- -

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

- -

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

- -

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 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
Oct 03, 2012
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
-0.38
CADD
Benign
0.053
DANN
Benign
0.81
PhyloP100
0.099
Mutation Taster
=87/13
polymorphism (auto)

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: rs35445420; hg19: chr2-179412966; API