chr2-178584378-C-T
Position:
Variant summary
Our verdict is Likely benign. Variant got -4 ACMG points: 1P and 5B. PP2BP4_StrongBP6
The NM_001267550.2(TTN):c.65173G>A(p.Val21725Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000719 in 1,613,160 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V21725A) has been classified as Likely benign.
Frequency
Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000075 ( 0 hom. )
Consequence
TTN
NM_001267550.2 missense
NM_001267550.2 missense
Scores
17
Clinical Significance
Conservation
PhyloP100: 1.72
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 Likely_benign. Variant got -4 ACMG points.
PP2
Missense variant in gene, where missense usually causes diseases (based on misZ statistic), TTN. . Gene score misZ -1.1021 (greater than the threshold 3.09). Trascript score misZ 6.9794 (greater than threshold 3.09). GenCC has associacion of gene with dilated cardiomyopathy, tibial muscular dystrophy, early-onset myopathy with fatal cardiomyopathy, autosomal recessive centronuclear myopathy, hypertrophic cardiomyopathy, hypertrophic cardiomyopathy 9, TTN-related myopathy, dilated cardiomyopathy 1G, arrhythmogenic right ventricular cardiomyopathy, myopathy, myofibrillar, 9, with early respiratory failure, familial isolated dilated cardiomyopathy, childhood-onset progressive contractures-limb-girdle weakness-muscle dystrophy syndrome, autosomal recessive limb-girdle muscular dystrophy type 2J.
BP4
Computational evidence support a benign effect (MetaRNN=0.040244758).
BP6
Variant 2-178584378-C-T is Benign according to our data. Variant chr2-178584378-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 228125.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=6}.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
|---|---|---|---|---|---|---|---|
| TTN | NM_001267550.2 | c.65173G>A | p.Val21725Ile | missense_variant | 311/363 | ENST00000589042.5 | |
| TTN-AS1 | NR_038272.1 | n.2768-195C>T | intron_variant, non_coding_transcript_variant |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| TTN | ENST00000589042.5 | c.65173G>A | p.Val21725Ile | missense_variant | 311/363 | 5 | NM_001267550.2 | P1 | |
| TTN-AS1 | ENST00000659121.1 | n.417-13218C>T | intron_variant, non_coding_transcript_variant |
Frequencies
GnomAD3 genomes 0.0000395 AC: 6AN: 152068Hom.: 0 Cov.: 32
GnomAD3 genomes
AF:
AC:
6
AN:
152068
Hom.:
Cov.:
32
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: 0.0000202 AC: 5AN: 248076Hom.: 0 AF XY: 0.00000743 AC XY: 1AN XY: 134564
GnomAD3 exomes
AF:
AC:
5
AN:
248076
Hom.:
AF XY:
AC XY:
1
AN XY:
134564
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: 0.0000753 AC: 110AN: 1461092Hom.: 0 Cov.: 32 AF XY: 0.0000633 AC XY: 46AN XY: 726834
GnomAD4 exome
AF:
AC:
110
AN:
1461092
Hom.:
Cov.:
32
AF XY:
AC XY:
46
AN XY:
726834
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 0.0000395 AC: 6AN: 152068Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2AN XY: 74250
GnomAD4 genome
AF:
AC:
6
AN:
152068
Hom.:
Cov.:
32
AF XY:
AC XY:
2
AN XY:
74250
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.:
TwinsUK
AF:
AC:
1
ALSPAC
AF:
AC:
0
ESP6500AA
AF:
AC:
0
ESP6500EA
AF:
AC:
1
ExAC
AF:
AC:
4
EpiCase
AF:
EpiControl
AF:
ClinVar
Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:6Benign:2
Revision: criteria provided, conflicting classifications
LINK: link
Submissions by phenotype
not provided Uncertain:1Benign:1
| Likely benign, criteria provided, single submitter | clinical testing | GeneDx | Feb 04, 2020 | - - |
| Uncertain significance, criteria provided, single submitter | clinical testing | Eurofins Ntd Llc (ga) | Feb 11, 2018 | - - |
Autosomal recessive limb-girdle muscular dystrophy type 2J Uncertain:1
| Uncertain significance, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Jan 13, 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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. - |
Dilated cardiomyopathy 1G Uncertain:1
| Uncertain significance, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Jan 13, 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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. - |
Early-onset myopathy with fatal cardiomyopathy Uncertain:1
| Uncertain significance, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Jan 13, 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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. - |
Tibial muscular dystrophy Uncertain:1
| Uncertain significance, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Jan 13, 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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. - |
Myopathy, myofibrillar, 9, with early respiratory failure Uncertain:1
| Uncertain significance, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Jan 13, 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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. - |
not specified Benign:1
| Likely benign, criteria provided, single submitter | clinical testing | Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine | Jun 22, 2015 | p.Val19157Ile in exon 260 of TTN: This variant is not expected to have clinical significance due to a lack of conservation across species, including mammals. Of note, 10 mammals have a isoleucine (Ile) at this position despite high nearby a mino acid conservation. In addition, computational prediction tools do not sugge st a high likelihood of impact to the protein. It has been identified in 4/66388 European chromosomes by the Exome Aggregation Consortium (ExAC, http://exac.bro adinstitute.org; dbSNP rs368716894). - |
Computational scores
Source:
Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
BayesDel_addAF
Benign
T
BayesDel_noAF
Benign
CADD
Benign
DANN
Benign
Eigen
Benign
Eigen_PC
Benign
FATHMM_MKL
Benign
D
LIST_S2
Benign
T;T;T;.;T;T;T
M_CAP
Benign
T
MetaRNN
Benign
T;T;T;T;T;T;T
MetaSVM
Benign
T
MutationAssessor
Benign
.;.;.;N;.;.;N
MutationTaster
Benign
D;D;D;D;D;D
PrimateAI
Benign
T
PROVEAN
Benign
N;N;.;.;N;N;.
REVEL
Benign
Sift
Benign
T;T;.;.;T;T;.
Polyphen
0.0020
.;.;.;B;.;.;B
Vest4
MVP
MPC
0.069
ClinPred
T
GERP RS
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