chr2-178718590-G-A

Position:

chr2-178718590-G-A

Variant summary

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

The NM_001267550.2(TTN):c.24516C>T(p.Thr8172=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.103 in 1,611,740 control chromosomes in the GnomAD database, including 8,963 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.089 ( 614 hom., cov: 33)

Exomes 𝑓: 0.10 ( 8349 hom. )

Consequence

TTN
NM_001267550.2 synonymous

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:21

Conservation

PhyloP100: -1.84

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 -21 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.82).

BP6

Variant 2-178718590-G-A is Benign according to our data. Variant chr2-178718590-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 46734.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178718590-G-A is described in Lovd as [Benign].

BP7

Synonymous conserved (PhyloP=-1.85 with no splicing effect.

BA1

GnomAd4 highest subpopulation (NFE) allele frequency at 95% confidence interval = 0.107 is higher than 0.05.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.24516C>T	p.Thr8172=	synonymous_variant	85/363	ENST00000589042.5	NP_001254479.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.24516C>T	p.Thr8172=	synonymous_variant	85/363	5	NM_001267550.2	ENSP00000467141	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.503-15914G>A		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.0894

AC:

13602

AN:

152070

Hom.:

614

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0744

Gnomad AMI

AF:

0.0636

Gnomad AMR

AF:

0.0645

Gnomad ASJ

AF:

0.0640

Gnomad EAS

AF:

0.0216

Gnomad SAS

AF:

0.102

Gnomad FIN

AF:

0.0996

Gnomad MID

AF:

0.0759

Gnomad NFE

AF:

0.109

Gnomad OTH

AF:

0.0886

GnomAD3 exomes

AF:

0.0878

AC:

21739

AN:

247616

Hom.:

1100

AF XY:

0.0921

AC XY:

12362

AN XY:

134278

show subpopulations

Gnomad AFR exome

AF:

0.0757

Gnomad AMR exome

AF:

0.0445

Gnomad ASJ exome

AF:

0.0662

Gnomad EAS exome

AF:

0.0205

Gnomad SAS exome

AF:

0.103

Gnomad FIN exome

AF:

0.0984

Gnomad NFE exome

AF:

0.109

Gnomad OTH exome

AF:

0.0937

GnomAD4 exome

AF:

0.104

AC:

151913

AN:

1459552

Hom.:

8349

Cov.:

AF XY:

0.105

AC XY:

76004

AN XY:

725752

show subpopulations

Gnomad4 AFR exome

AF:

0.0718

Gnomad4 AMR exome

AF:

0.0471

Gnomad4 ASJ exome

AF:

0.0658

Gnomad4 EAS exome

AF:

0.0211

Gnomad4 SAS exome

AF:

0.107

Gnomad4 FIN exome

AF:

0.0970

Gnomad4 NFE exome

AF:

0.112

Gnomad4 OTH exome

AF:

0.0974

GnomAD4 genome

AF:

0.0895

AC:

13614

AN:

152188

Hom.:

614

Cov.:

AF XY:

0.0888

AC XY:

6608

AN XY:

74382

show subpopulations

Gnomad4 AFR

AF:

0.0742

Gnomad4 AMR

AF:

0.0644

Gnomad4 ASJ

AF:

0.0640

Gnomad4 EAS

AF:

0.0216

Gnomad4 SAS

AF:

0.104

Gnomad4 FIN

AF:

0.0996

Gnomad4 NFE

AF:

0.109

Gnomad4 OTH

AF:

0.0877

Alfa

AF:

0.0983

Hom.:

414

Bravo

AF:

0.0846

Asia WGS

AF:

0.0650

AC:

224

AN:

3478

EpiCase

AF:

0.106

EpiControl

AF:

0.106

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:21

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:8

Benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Aug 09, 2019	- -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -
Benign, criteria provided, single submitter	clinical testing	PreventionGenetics, part of Exact Sciences	-	- -
Benign, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Aug 15, 2013	- -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Nov 01, 2012	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	Eurofins Ntd Llc (ga)	Jun 27, 2014	- -
Benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Apr 11, 2012	- -
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: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 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 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. -

Early-onset myopathy with fatal cardiomyopathy

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 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 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. -

not provided

Benign:2

Benign, criteria provided, single submitter	clinical testing	Athena Diagnostics	Jun 21, 2018	- -
Likely benign, criteria provided, single submitter	not provided	Breakthrough Genomics, Breakthrough Genomics	-	- -

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 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 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 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 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 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 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. -

Cardiovascular phenotype

Benign:1

Benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 22, 2015

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

-0.82

CADD

Benign

1.2

DANN

Benign

0.54

Splicing

Name

Calibrated prediction

Score

Prediction

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

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