rs140002940

Variant summary

Our verdict is Benign. The variant received -15 ACMG points: 1P and 16B. PP3BP6_Very_StrongBS1BS2

The NM_001267550.2(TTN):​c.42024+6T>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000981 in 1,610,488 control chromosomes in the GnomAD database, including 17 homozygotes. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0049 ( 5 hom., cov: 32)
Exomes 𝑓: 0.00057 ( 12 hom. )

Consequence

TTN
NM_001267550.2 splice_region, intron

Scores

2
Splicing: ADA: 0.9733
2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:23

Conservation

PhyloP100: 3.05

Publications

2 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 -15 ACMG points.

PP3
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
BP6
Variant 2-178635159-A-G is Benign according to our data. Variant chr2-178635159-A-G is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 46951.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 = 0.00495 (753/152176) while in subpopulation AFR AF = 0.0165 (684/41546). AF 95% confidence interval is 0.0154. There are 5 homozygotes in GnomAd4. There are 380 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
BS2
High Homozygotes in GnomAd4 at 5 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.42024+6T>C splice_region_variant, intron_variant Intron 228 of 362 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.42024+6T>C splice_region_variant, intron_variant Intron 228 of 362 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.00491
AC:
746
AN:
152058
Hom.:
4
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0163
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00262
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00949
Gnomad NFE
AF:
0.000206
Gnomad OTH
AF:
0.00575
GnomAD2 exomes
AF:
0.00125
AC:
308
AN:
245924
AF XY:
0.000961
show subpopulations
Gnomad AFR exome
AF:
0.0144
Gnomad AMR exome
AF:
0.00157
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000465
Gnomad NFE exome
AF:
0.000161
Gnomad OTH exome
AF:
0.00184
GnomAD4 exome
AF:
0.000567
AC:
827
AN:
1458312
Hom.:
12
Cov.:
32
AF XY:
0.000487
AC XY:
353
AN XY:
725270
show subpopulations
African (AFR)
AF:
0.0167
AC:
555
AN:
33166
American (AMR)
AF:
0.00187
AC:
82
AN:
43902
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26072
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39606
South Asian (SAS)
AF:
0.0000469
AC:
4
AN:
85366
European-Finnish (FIN)
AF:
0.0000562
AC:
3
AN:
53366
Middle Eastern (MID)
AF:
0.00139
AC:
8
AN:
5742
European-Non Finnish (NFE)
AF:
0.0000648
AC:
72
AN:
1110852
Other (OTH)
AF:
0.00171
AC:
103
AN:
60240
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.491
Heterozygous variant carriers
0
44
88
131
175
219
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome 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
GnomAD4 genome
AF:
0.00495
AC:
753
AN:
152176
Hom.:
5
Cov.:
32
AF XY:
0.00511
AC XY:
380
AN XY:
74376
show subpopulations
African (AFR)
AF:
0.0165
AC:
684
AN:
41546
American (AMR)
AF:
0.00262
AC:
40
AN:
15260
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5140
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.0102
AC:
3
AN:
294
European-Non Finnish (NFE)
AF:
0.000206
AC:
14
AN:
67990
Other (OTH)
AF:
0.00569
AC:
12
AN:
2110
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.499
Heterozygous variant carriers
0
41
83
124
166
207
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
10
20
30
40
50
<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:
0.00204
Hom.:
0
Bravo
AF:
0.00590
Asia WGS
AF:
0.000866
AC:
3
AN:
3478
EpiCase
AF:
0.000109
EpiControl
AF:
0.000296

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:23
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:7
May 01, 2014
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

- -

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

- -

Oct 30, 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.34320+6T>C alters a conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Several computational tools predict a significant impact on normal splicing: two predict the variant abolishes a 5' splicing donor site; one predicts the variant weakens a 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.0013 in 245924 control chromosomes, predominantly at a frequency of 0.014 within the African or African-American subpopulation in the gnomAD database, including 1 homozygotes. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 22 fold of 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 African or African-American origin. To our knowledge, no occurrence of c.34320+6T>C in individuals affected with Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as benign. Based on the evidence outlined above, the variant was classified as benign. -

Apr 21, 2017
Athena Diagnostics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mar 02, 2012
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

34320+6T>C in intron 177 of TTN: This variant is not expected to have clinical s ignificance because it has been identified in 1.5% (44/2980) of African American chromosomes from a broad population by the NHLBI Exome Sequencing Project (http ://evs.gs.washington.edu/EVS; dbSNP rs140002940). -

Aug 14, 2014
Genetic Services Laboratory, University of Chicago
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Benign:4
-
Clinical Genetics, Academic Medical Center
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

- -

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

- -

Jun 21, 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
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. -

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

- -

Early-onset myopathy with fatal cardiomyopathy Benign:2
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. -

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 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. -

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

- -

Tibial muscular dystrophy Benign:2
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. -

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

- -

TTN-related disorder Benign:1
May 29, 2019
PreventionGenetics, part of Exact Sciences
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
Feb 02, 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. -

Cardiomyopathy Benign:1
Oct 17, 2017
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.51
CADD
Uncertain
23
DANN
Benign
0.74
PhyloP100
3.0
Mutation Taster
=100/0
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
0.97
dbscSNV1_RF
Pathogenic
0.87
SpliceAI score (max)
0.060
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: rs140002940; hg19: chr2-179499886; API