2-178717998-G-A
Position:
Variant summary
Our verdict is Benign. Variant got -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2
The NM_001267550.2(TTN):c.25008C>T(p.Cys8336=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00075 in 1,613,766 control chromosomes in the GnomAD database, including 10 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).
Frequency
Genomes: 𝑓 0.0039 ( 3 hom., cov: 33)
Exomes 𝑓: 0.00043 ( 7 hom. )
Consequence
TTN
NM_001267550.2 synonymous
NM_001267550.2 synonymous
Scores
2
Clinical Significance
Conservation
PhyloP100: 2.63
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]
Genome browser will be placed here
ACMG classification
Classification made for transcript
Verdict is Benign. Variant got -21 ACMG points.
BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.51).
BP6
Variant 2-178717998-G-A is Benign according to our data. Variant chr2-178717998-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 46747.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178717998-G-A is described in Lovd as [Benign].
BP7
Synonymous conserved (PhyloP=2.63 with no splicing effect.
BS1
Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00387 (589/152288) while in subpopulation AFR AF= 0.0134 (558/41562). AF 95% confidence interval is 0.0125. There are 3 homozygotes in gnomad4. There are 292 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.
BS2
High Homozygotes in GnomAd4 at 3 AD,AR gene
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| TTN | NM_001267550.2 | c.25008C>T | p.Cys8336= | synonymous_variant | 86/363 | ENST00000589042.5 | NP_001254479.2 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| TTN | ENST00000589042.5 | c.25008C>T | p.Cys8336= | synonymous_variant | 86/363 | 5 | NM_001267550.2 | ENSP00000467141 | P1 | |
| TTN-AS1 | ENST00000659121.1 | n.503-16506G>A | intron_variant, non_coding_transcript_variant |
Frequencies
GnomAD3 genomes 0.00386 AC: 587AN: 152170Hom.: 3 Cov.: 33
GnomAD3 genomes
AF:
AC:
587
AN:
152170
Hom.:
Cov.:
33
Gnomad AFR
AF:
Gnomad AMI
AF:
Gnomad AMR
AF:
Gnomad ASJ
AF:
Gnomad EAS
AF:
Gnomad SAS
AF:
Gnomad FIN
AF:
Gnomad MID
AF:
Gnomad NFE
AF:
Gnomad OTH
AF:
GnomAD3 exomes AF: 0.000889 AC: 221AN: 248574Hom.: 1 AF XY: 0.000801 AC XY: 108AN XY: 134830
GnomAD3 exomes
AF:
AC:
221
AN:
248574
Hom.:
AF XY:
AC XY:
108
AN XY:
134830
Gnomad AFR exome
AF:
Gnomad AMR exome
AF:
Gnomad ASJ exome
AF:
Gnomad EAS exome
AF:
Gnomad SAS exome
AF:
Gnomad FIN exome
AF:
Gnomad NFE exome
AF:
Gnomad OTH exome
AF:
GnomAD4 exome AF: 0.000426 AC: 622AN: 1461478Hom.: 7 Cov.: 35 AF XY: 0.000369 AC XY: 268AN XY: 727010
GnomAD4 exome
AF:
AC:
622
AN:
1461478
Hom.:
Cov.:
35
AF XY:
AC XY:
268
AN XY:
727010
Gnomad4 AFR exome
AF:
Gnomad4 AMR exome
AF:
Gnomad4 ASJ exome
AF:
Gnomad4 EAS exome
AF:
Gnomad4 SAS exome
AF:
Gnomad4 FIN exome
AF:
Gnomad4 NFE exome
AF:
Gnomad4 OTH exome
AF:
GnomAD4 genome 0.00387 AC: 589AN: 152288Hom.: 3 Cov.: 33 AF XY: 0.00392 AC XY: 292AN XY: 74464
GnomAD4 genome
AF:
AC:
589
AN:
152288
Hom.:
Cov.:
33
AF XY:
AC XY:
292
AN XY:
74464
Gnomad4 AFR
AF:
Gnomad4 AMR
AF:
Gnomad4 ASJ
AF:
Gnomad4 EAS
AF:
Gnomad4 SAS
AF:
Gnomad4 FIN
AF:
Gnomad4 NFE
AF:
Gnomad4 OTH
AF:
Alfa
AF:
Hom.:
Bravo
AF:
Asia WGS
AF:
AC:
4
AN:
3478
EpiCase
AF:
EpiControl
AF:
ClinVar
Significance: Benign/Likely benign
Submissions summary: Benign:17
Revision: criteria provided, multiple submitters, no conflicts
LINK: link
Submissions by phenotype
not specified Benign:5
| Benign, no assertion criteria provided | clinical testing | Clinical Genetics, Academic Medical Center | - | - - |
| Benign, criteria provided, single submitter | clinical testing | GeneDx | Apr 29, 2014 | 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. - |
| Benign, criteria provided, single submitter | clinical testing | Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine | Mar 19, 2012 | p.Cys7092Cys in Exon 83 of TTN: This variant is not expected to have clinical si gnificance because it does not alter an amino acid residue, is not located withi n the splice consensus sequence and has been identified in 1.1% (37/3360) of Afr ican American chromosomes from a broad population by the NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS; dbSNP rs116378128). - |
| Benign, no assertion criteria provided | clinical testing | Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center | - | - - |
| Benign, criteria provided, single submitter | clinical testing | Women's Health and Genetics/Laboratory Corporation of America, LabCorp | Feb 03, 2020 | Variant summary: TTN c.21276C>T alters a conserved nucleotide resulting in a synonymous change. Several computational tools predict a significant impact on normal splicing: Two predict the variant creates a 5' donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.00089 in 248574 control chromosomes in the gnomAD database, including 1 homozygotes. The observed variant frequency is approximately 1.4 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 benign. To our knowledge, no occurrence of c.21276C>T in individuals affected with Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Both laboratories classified the variant as benign. Based on the evidence outlined above, the variant was classified as benign. - |
Autosomal recessive limb-girdle muscular dystrophy type 2J Benign:2
| Benign, criteria provided, single submitter | clinical testing | Genome-Nilou Lab | Sep 10, 2021 | - - |
| Likely benign, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Jan 12, 2018 | 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
| Benign, criteria provided, single submitter | clinical testing | Genome-Nilou Lab | Sep 10, 2021 | - - |
| Likely benign, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Jan 12, 2018 | 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. - |
not provided Benign:2
| Benign, criteria provided, single submitter | clinical testing | Athena Diagnostics | Sep 12, 2017 | - - |
| Benign, criteria provided, single submitter | clinical testing | CeGaT Center for Human Genetics Tuebingen | Apr 01, 2024 | TTN: BP4, BS1, BS2 - |
Tibial muscular dystrophy Benign:2
| Benign, criteria provided, single submitter | clinical testing | Genome-Nilou Lab | Sep 10, 2021 | - - |
| Benign, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Jan 12, 2018 | 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
| Benign, criteria provided, single submitter | clinical testing | Genome-Nilou Lab | Sep 10, 2021 | - - |
| Benign, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Jan 12, 2018 | 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
| Benign, criteria provided, single submitter | clinical testing | Labcorp Genetics (formerly Invitae), Labcorp | Feb 01, 2024 | - - |
Dilated cardiomyopathy 1G Benign:1
| Likely benign, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Jan 12, 2018 | 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. - |
Computational scores
Source:
Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
CADD
Benign
DANN
Benign
Splicing
Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
Details are displayed if max score is > 0.2
Find out detailed SpliceAI scores and Pangolin per-transcript scores at