2-178717336-A-T

Position:

chr2-178717336-A-T

Variant summary

Our verdict is Benign. Variant got -19 ACMG points: 1P and 20B. PP2BP4_StrongBP6_Very_StrongBA1

The NM_001267550.2(TTN):c.25398T>A(p.Asp8466Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0066 in 1,613,454 control chromosomes in the GnomAD database, including 319 homozygotes. In-silico tool predicts a benign outcome for this variant. 13/17 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D8466G) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.024 ( 141 hom., cov: 33)

Exomes 𝑓: 0.0048 ( 178 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:25

Conservation

PhyloP100: -0.126

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 -19 ACMG points.

PP2

Missense variant where missense usually causes diseases, TTN

BP4

Computational evidence support a benign effect (MetaRNN=0.002010703).

BP6

Variant 2-178717336-A-T is Benign according to our data. Variant chr2-178717336-A-T is described in ClinVar as [Likely_benign]. Clinvar id is 46758.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178717336-A-T is described in Lovd as [Benign]. Variant chr2-178717336-A-T is described in Lovd as [Likely_benign].

BA1

GnomAd4 highest subpopulation (AFR) allele frequency at 95% confidence interval = 0.0736 is higher than 0.05.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.25398T>A	p.Asp8466Glu	missense_variant	88/363	ENST00000589042.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.25398T>A	p.Asp8466Glu	missense_variant	88/363	5	NM_001267550.2	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.503-17168A>T		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.0240

AC:

3646

AN:

152168

Hom.:

140

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0757

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0113

Gnomad ASJ

AF:

0.00720

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.0241

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00949

Gnomad NFE

AF:

0.00207

Gnomad OTH

AF:

0.0253

GnomAD3 exomes

AF:

0.00956

AC:

2374

AN:

248422

Hom.:

AF XY:

0.00920

AC XY:

1240

AN XY:

134722

show subpopulations

Gnomad AFR exome

AF:

0.0752

Gnomad AMR exome

AF:

0.00481

Gnomad ASJ exome

AF:

0.00648

Gnomad EAS exome

AF:

0.0000557

Gnomad SAS exome

AF:

0.0220

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00232

Gnomad OTH exome

AF:

0.00748

GnomAD4 exome

AF:

0.00478

AC:

6989

AN:

1461168

Hom.:

178

Cov.:

AF XY:

0.00506

AC XY:

3676

AN XY:

726836

show subpopulations

Gnomad4 AFR exome

AF:

0.0755

Gnomad4 AMR exome

AF:

0.00541

Gnomad4 ASJ exome

AF:

0.00773

Gnomad4 EAS exome

AF:

0.000202

Gnomad4 SAS exome

AF:

0.0211

Gnomad4 FIN exome

AF:

0.0000749

Gnomad4 NFE exome

AF:

0.00142

Gnomad4 OTH exome

AF:

0.00928

GnomAD4 genome

AF:

0.0241

AC:

3663

AN:

152286

Hom.:

141

Cov.:

AF XY:

0.0237

AC XY:

1764

AN XY:

74474

show subpopulations

Gnomad4 AFR

AF:

0.0758

Gnomad4 AMR

AF:

0.0112

Gnomad4 ASJ

AF:

0.00720

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.0247

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00207

Gnomad4 OTH

AF:

0.0250

Alfa

AF:

0.00356

Hom.:

Bravo

AF:

0.0266

TwinsUK

AF:

0.000539

AC:

ALSPAC

AF:

0.00182

AC:

ESP6500AA

AF:

0.0694

AC:

260

ESP6500EA

AF:

0.00268

AC:

ExAC

AF:

0.0112

AC:

1351

Asia WGS

AF:

0.0170

AC:

AN:

3478

EpiCase

AF:

0.00322

EpiControl

AF:

0.00332

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:25

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:10

Likely benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Mar 28, 2024	- -
Benign, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -
Benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Mar 01, 2012	Asp7222Glu in exon 85 of TTN: This variant is not expected to have clinical sign ificance because it has been identified in 6.8% (207/3054) of African American c hromosomes from a broad population by the NHLBI Exome Sequencing Project (http:/ /evs.gs.washington.edu/EVS; dbSNP rs72648986). -
Benign, criteria provided, single submitter	research	Biesecker Lab/Clinical Genomics Section, National Institutes of Health	Jun 24, 2013	- -
Benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Oct 18, 2013	- -
Benign, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Aug 15, 2013	- -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Dec 06, 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	PreventionGenetics, part of Exact Sciences	-	- -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -

not provided

Benign:3

Likely benign, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Likely benign, no assertion criteria provided	clinical testing	Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)	-	- -
Benign, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Dec 21, 2022	- -

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 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. -

Early-onset myopathy with fatal cardiomyopathy

Benign:2

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. -
Benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 10, 2021	- -

Tibial muscular dystrophy

Benign:2

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. -
Benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 10, 2021	- -

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

Invitae

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. -

Cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

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

Nov 18, 2022

- -

Cardiovascular phenotype

Benign:1

Benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 14, 2012

This alteration is classified as benign based on a combination of the following: 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

AlphaMissense

Benign

0.17

BayesDel_addAF

Benign

-0.61

BayesDel_noAF

Benign

-0.59

CADD

Benign

DANN

Benign

0.84

Eigen

Benign

-0.39

Eigen_PC

Benign

-0.17

FATHMM_MKL

Benign

0.71

LIST_S2

Benign

0.63

T;T;.;T

MetaRNN

Benign

0.0020

T;T;T;T

MetaSVM

Benign

-1.1

MutationTaster

Benign

1.0

D;D;D;N;N;N

PrimateAI

Uncertain

0.54

PROVEAN

Benign

-1.7

N;.;.;.

REVEL

Benign

0.11

Sift

Benign

0.42

T;.;.;.

Polyphen

0.0010

.;.;B;B

Vest4

0.067

MutPred

0.40

.;.;Loss of ubiquitination at K8144 (P = 0.1087);Loss of ubiquitination at K8144 (P = 0.1087);

MPC

0.078

ClinPred

0.0016

GERP RS

4.6

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