rs72648984

Positions:

chr2-178718033-T-C

Variant summary

Our verdict is Benign. Variant got -19 ACMG points: 1P and 20B. PP2BP4_StrongBP6_Very_StrongBS1BS2

The NM_001267550.2(TTN):c.24973A>G(p.Lys8325Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00569 in 1,613,834 control chromosomes in the GnomAD database, including 48 homozygotes. In-silico tool predicts a benign outcome for this variant. 12/17 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0047 ( 1 hom., cov: 32)

Exomes 𝑓: 0.0058 ( 47 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 1.54

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:):

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 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=0.00819537).

BP6

Variant 2-178718033-T-C is Benign according to our data. Variant chr2-178718033-T-C is described in ClinVar as [Likely_benign]. Clinvar id is 46745.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178718033-T-C is described in Lovd as [Benign]. Variant chr2-178718033-T-C is described in Lovd as [Likely_benign].

BS1

Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.00466 (710/152334) while in subpopulation NFE AF= 0.00682 (464/68014). AF 95% confidence interval is 0.00631. There are 1 homozygotes in gnomad4. There are 373 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

BS2

High Homozygotes in GnomAdExome4 at 47 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.24973A>G	p.Lys8325Glu	missense_variant	86/363	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.24973A>G	p.Lys8325Glu	missense_variant	86/363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.00466

AC:

710

AN:

152216

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00118

Gnomad AMI

AF:

0.00110

Gnomad AMR

AF:

0.00151

Gnomad ASJ

AF:

0.000288

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.0158

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00682

Gnomad OTH

AF:

0.00143

GnomAD3 exomes

AF:

0.00555

AC:

1380

AN:

248740

Hom.:

AF XY:

0.00560

AC XY:

756

AN XY:

134922

show subpopulations

Gnomad AFR exome

AF:

0.00129

Gnomad AMR exome

AF:

0.000464

Gnomad ASJ exome

AF:

0.000298

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0152

Gnomad NFE exome

AF:

0.00880

Gnomad OTH exome

AF:

0.00398

GnomAD4 exome

AF:

0.00580

AC:

8477

AN:

1461500

Hom.:

Cov.:

AF XY:

0.00566

AC XY:

4113

AN XY:

727036

show subpopulations

Gnomad4 AFR exome

AF:

0.000956

Gnomad4 AMR exome

AF:

0.000492

Gnomad4 ASJ exome

AF:

0.000191

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.0150

Gnomad4 NFE exome

AF:

0.00665

Gnomad4 OTH exome

AF:

0.00376

GnomAD4 genome

AF:

0.00466

AC:

710

AN:

152334

Hom.:

Cov.:

AF XY:

0.00501

AC XY:

373

AN XY:

74482

show subpopulations

Gnomad4 AFR

AF:

0.00118

Gnomad4 AMR

AF:

0.00150

Gnomad4 ASJ

AF:

0.000288

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.0158

Gnomad4 NFE

AF:

0.00682

Gnomad4 OTH

AF:

0.00142

Alfa

AF:

0.00590

Hom.:

Bravo

AF:

0.00343

TwinsUK

AF:

0.00809

AC:

ALSPAC

AF:

0.00830

AC:

ESP6500AA

AF:

0.00177

AC:

ESP6500EA

AF:

0.00758

AC:

ExAC

AF:

0.00613

AC:

741

EpiCase

AF:

0.00491

EpiControl

AF:

0.00616

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:25

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:9

Benign, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -
Benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Apr 23, 2015	p.Lys7081Glu in exon 83 of TTN: This variant is not expected to have clinical si gnificance because it has been identified in 1.5% (99/6614) of Finnish chromosom es and 0.9% (623/66712) of European chromosomes by the Exome Aggregation Consort ium (ExAC, http://exac.broadinstitute.org; dbSNP rs72648984). -
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	GeneDx	Nov 07, 2016	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	Athena Diagnostics	Nov 05, 2019	- -
Benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Aug 19, 2015	- -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -
Benign, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -
Likely benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	May 29, 2021	- -

not provided

Benign:4

Likely benign, no assertion criteria provided	clinical testing	Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)	-	- -
Likely benign, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jul 01, 2024	TTN: BS2 -
Likely benign, criteria provided, single submitter	not provided	Breakthrough Genomics, Breakthrough Genomics	-	- -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Benign:2

Benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 10, 2021	- -
Likely benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Apr 27, 2017	This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases allowed determination this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -

Early-onset myopathy with fatal cardiomyopathy

Benign:2

Benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 10, 2021	- -
Likely benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Apr 27, 2017	This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases allowed determination this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -

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	Apr 27, 2017	This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -

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	Apr 27, 2017	This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -

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

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases allowed determination this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -

Cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Center for Advanced Laboratory Medicine, UC San Diego Health, University of California San Diego

Feb 26, 2019

- -

Cardiovascular phenotype

Benign:1

Benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 19, 2021

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

AlphaMissense

Benign

0.20

BayesDel_addAF

Benign

-0.38

BayesDel_noAF

Benign

-0.31

CADD

Benign

DANN

Benign

0.91

Eigen

Benign

-0.025

Eigen_PC

Benign

0.18

FATHMM_MKL

Uncertain

0.83

LIST_S2

Benign

0.72

T;T;.;T

MetaRNN

Benign

0.0082

T;T;T;T

MetaSVM

Benign

-0.88

PrimateAI

Uncertain

0.53

PROVEAN

Benign

-1.5

N;.;.;.

REVEL

Benign

0.19

Sift

Benign

0.68

T;.;.;.

Polyphen

0.22

.;.;B;B

Vest4

0.35

MVP

0.26

MPC

0.14

ClinPred

0.019

GERP RS

6.2

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.030

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