2-178604881-T-G

Position:

chr2-178604881-T-G

Variant summary

Our verdict is Benign. Variant got -14 ACMG points: 0P and 14B. BP4_ModerateBP6_Very_StrongBS1

The NM_001267550.2(TTN):c.54208A>C(p.Arg18070Arg) variant causes a synonymous change. The variant allele was found at a frequency of 0.000376 in 1,611,868 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0020 ( 1 hom., cov: 32)

Exomes 𝑓: 0.00021 ( 0 hom. )

Consequence

TTN
NM_001267550.2 synonymous

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:17

Conservation

PhyloP100: 4.88

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 links:

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]

TTN-AS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -14 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.37).

BP6

Variant 2-178604881-T-G is Benign according to our data. Variant chr2-178604881-T-G is described in ClinVar as [Likely_benign]. Clinvar id is 47088.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178604881-T-G is described in Lovd as [Likely_benign]. Variant chr2-178604881-T-G is described in Lovd as [Benign].

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00195 (297/152040) while in subpopulation AFR AF= 0.00679 (282/41538). AF 95% confidence interval is 0.00614. There are 1 homozygotes in gnomad4. There are 138 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.54208A>C	p.Arg18070Arg	synonymous_variant	281/363	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 link	c.54208A>C	p.Arg18070Arg	synonymous_variant	281/363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.00195

AC:

297

AN:

151922

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00681

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000919

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.000479

GnomAD3 exomes

AF:

0.000538

AC:

133

AN:

247300

Hom.:

AF XY:

0.000410

AC XY:

AN XY:

134186

show subpopulations

Gnomad AFR exome

AF:

0.00790

Gnomad AMR exome

AF:

0.000292

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.000167

GnomAD4 exome

AF:

0.000212

AC:

309

AN:

1459828

Hom.:

Cov.:

AF XY:

0.000179

AC XY:

130

AN XY:

726124

show subpopulations

Gnomad4 AFR exome

AF:

0.00806

Gnomad4 AMR exome

AF:

0.000269

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

9.00e-7

Gnomad4 OTH exome

AF:

0.000448

GnomAD4 genome

AF:

0.00195

AC:

297

AN:

152040

Hom.:

Cov.:

AF XY:

0.00186

AC XY:

138

AN XY:

74330

show subpopulations

Gnomad4 AFR

AF:

0.00679

Gnomad4 AMR

AF:

0.000918

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.000474

Alfa

AF:

0.000884

Hom.:

Bravo

AF:

0.00231

Asia WGS

AF:

0.000289

AC:

AN:

3478

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, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	May 18, 2023	- -
Benign, criteria provided, single submitter	clinical testing	Athena Diagnostics	Jan 05, 2021	- -
Benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Dec 06, 2012	Arg15502Arg in exon 230 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, has been identified in 1.0% (38/3784) of Africa n American chromosomes from a broad population by the NHLBI Exome Sequencing Pro ject (http://evs.gs.washington.edu/EVS/dbSNP rs138240658). Arg15502Arg in exon 230 of TTN (rs138240658; allele frequency= 1.0%, 38/3784) ** -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -
Benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jan 25, 2018	- -

not provided

Benign:4

Benign, criteria provided, single submitter	clinical testing	GeneDx	Mar 03, 2015	- -
Likely benign, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, University Medical Center Utrecht	-	- -
Likely benign, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Sep 06, 2023	- -
Likely benign, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

TTN-related disorder

Benign:1

Likely benign, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Mar 29, 2019

This variant is classified as likely 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

Benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 31, 2024

- -

Cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Apr 05, 2016

- -

Early-onset myopathy with fatal cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Tibial muscular dystrophy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Myopathy, myofibrillar, 9, with early respiratory failure

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Cardiovascular phenotype

Benign:1

Benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 03, 2016

This 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

-0.37

CADD

Benign

4.6

DANN

Benign

0.86

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over