rs746578

Variant summary

Our verdict is Benign. Variant got -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BA1

The NM_001267550.2(TTN):​c.12780G>T​(p.Ala4260Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0527 in 1,613,230 control chromosomes in the GnomAD database, including 3,833 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★). Synonymous variant affecting the same amino acid position (i.e. A4260A) has been classified as Benign.

Frequency

Genomes: 𝑓 0.050 ( 381 hom., cov: 32)
Exomes 𝑓: 0.053 ( 3452 hom. )

Consequence

TTN
NM_001267550.2 synonymous

Scores

2

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:18

Conservation

PhyloP100: -0.0990
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]

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -21 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.77).
BP6
Variant 2-178740453-C-A is Benign according to our data. Variant chr2-178740453-C-A is described in ClinVar as [Benign]. Clinvar id is 47831.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178740453-C-A is described in Lovd as [Benign]. Variant chr2-178740453-C-A is described in Lovd as [Likely_benign].
BP7
Synonymous conserved (PhyloP=-0.099 with no splicing effect.
BA1
GnomAd4 highest subpopulation (EAS) allele frequency at 95% confidence interval = 0.179 is higher than 0.05.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
TTNNM_001267550.2 linkuse as main transcriptc.12780G>T p.Ala4260Ala synonymous_variant 48/363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkuse as main transcriptc.12780G>T p.Ala4260Ala synonymous_variant 48/3635 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.0501
AC:
7612
AN:
151978
Hom.:
380
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0116
Gnomad AMI
AF:
0.0484
Gnomad AMR
AF:
0.137
Gnomad ASJ
AF:
0.0487
Gnomad EAS
AF:
0.189
Gnomad SAS
AF:
0.0237
Gnomad FIN
AF:
0.0515
Gnomad MID
AF:
0.0158
Gnomad NFE
AF:
0.0454
Gnomad OTH
AF:
0.0465
GnomAD3 exomes
AF:
0.0795
AC:
19697
AN:
247814
Hom.:
1691
AF XY:
0.0700
AC XY:
9412
AN XY:
134410
show subpopulations
Gnomad AFR exome
AF:
0.0109
Gnomad AMR exome
AF:
0.241
Gnomad ASJ exome
AF:
0.0485
Gnomad EAS exome
AF:
0.208
Gnomad SAS exome
AF:
0.0190
Gnomad FIN exome
AF:
0.0521
Gnomad NFE exome
AF:
0.0444
Gnomad OTH exome
AF:
0.0671
GnomAD4 exome
AF:
0.0530
AC:
77372
AN:
1461134
Hom.:
3452
Cov.:
33
AF XY:
0.0512
AC XY:
37191
AN XY:
726796
show subpopulations
Gnomad4 AFR exome
AF:
0.00932
Gnomad4 AMR exome
AF:
0.229
Gnomad4 ASJ exome
AF:
0.0474
Gnomad4 EAS exome
AF:
0.189
Gnomad4 SAS exome
AF:
0.0201
Gnomad4 FIN exome
AF:
0.0546
Gnomad4 NFE exome
AF:
0.0452
Gnomad4 OTH exome
AF:
0.0516
GnomAD4 genome
AF:
0.0501
AC:
7615
AN:
152096
Hom.:
381
Cov.:
32
AF XY:
0.0517
AC XY:
3840
AN XY:
74338
show subpopulations
Gnomad4 AFR
AF:
0.0116
Gnomad4 AMR
AF:
0.138
Gnomad4 ASJ
AF:
0.0487
Gnomad4 EAS
AF:
0.189
Gnomad4 SAS
AF:
0.0230
Gnomad4 FIN
AF:
0.0515
Gnomad4 NFE
AF:
0.0454
Gnomad4 OTH
AF:
0.0451
Alfa
AF:
0.0130
Hom.:
512
EpiCase
AF:
0.0407
EpiControl
AF:
0.0430

ClinVar

Significance: Benign
Submissions summary: Benign:18
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:7
Benign, no assertion criteria providedclinical testingGenome Diagnostics Laboratory, University Medical Center Utrecht-- -
Benign, criteria provided, single submitterclinical testingPreventionGenetics, part of Exact Sciences-- -
Benign, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineApr 26, 2012Ala4022Ala in exon 45B of TTN: This variant is not expected to have clinical sig nificance because it does not alter an amino acid residue and is not located wit hin the splice consensus sequence. It has been identified in 12.8% (860/6670) of European American chromosomes from a broad population by the NHLBI Exome Sequen cing Project (http://evs.gs.washington.edu/EVS/; rs746578). -
Benign, no assertion criteria providedclinical testingClinical Genetics, Academic Medical Center-- -
Benign, no assertion criteria providedclinical testingClinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center-- -
Benign, criteria provided, single submitterclinical testingGeneDxOct 19, 2012This 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 submitterclinical testingEurofins Ntd Llc (ga)Jul 23, 2015- -
not provided Benign:3
Benign, criteria provided, single submitternot providedBreakthrough Genomics, Breakthrough Genomics-- -
Likely benign, no assertion criteria providedclinical testingLaboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)-- -
Likely benign, no assertion criteria providedclinical testingDiagnostic Laboratory, Department of Genetics, University Medical Center Groningen-- -
Autosomal recessive limb-girdle muscular dystrophy type 2J Benign:1
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
Benign, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpFeb 01, 2024- -
Cardiomyopathy Benign:1
Benign, criteria provided, single submitterclinical testingCHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern OntarioNov 30, 2015- -
Early-onset myopathy with fatal cardiomyopathy Benign:1
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1838244:Tibial muscular dystrophy;C1858763:Dilated cardiomyopathy 1G;C1861065:Hypertrophic cardiomyopathy 9;C1863599:Myopathy, myofibrillar, 9, with early respiratory failure;C2673677:Early-onset myopathy with fatal cardiomyopathy Benign:1
Benign, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsAug 02, 2021- -
Tibial muscular dystrophy Benign:1
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Myopathy, myofibrillar, 9, with early respiratory failure Benign:1
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Cardiovascular phenotype Benign:1
Benign, criteria provided, single submitterclinical testingAmbry GeneticsJun 24, 2015This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, 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
-0.77
CADD
Benign
0.19
DANN
Benign
0.73

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs746578; hg19: chr2-179605180; COSMIC: COSV60241877; COSMIC: COSV60241877; API