2-178717244-C-T

Position:

chr2-178717244-C-T

Variant summary

Our verdict is Benign. Variant got -13 ACMG points: 0P and 13B. BP4_StrongBP6BS1BS2

The NM_001267550.2(TTN):c.25490G>A(p.Arg8497His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00221 in 1,613,648 control chromosomes in the GnomAD database, including 52 homozygotes. In-silico tool predicts a benign outcome for this variant. 11/17 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0018 ( 5 hom., cov: 32)

Exomes 𝑓: 0.0023 ( 47 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:20

Conservation

PhyloP100: 1.59

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 -13 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.005892992).

BP6

Variant 2-178717244-C-T is Benign according to our data. Variant chr2-178717244-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 46759.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=1, Likely_benign=5, Benign=10}. Variant chr2-178717244-C-T is described in Lovd as [Benign]. Variant chr2-178717244-C-T is described in Lovd as [Likely_benign].

BS1

Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.00179 (272/152244) while in subpopulation SAS AF= 0.0245 (118/4818). AF 95% confidence interval is 0.0209. There are 5 homozygotes in gnomad4. There are 156 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

BS2

High Homozygotes in GnomAd4 at 5 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.25490G>A	p.Arg8497His	missense_variant	88/363	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 link	c.25490G>A	p.Arg8497His	missense_variant	88/363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.00177

AC:

269

AN:

152126

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000169

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00170

Gnomad ASJ

AF:

0.000864

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.0238

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00168

Gnomad OTH

AF:

0.00144

GnomAD3 exomes

AF:

0.00376

AC:

936

AN:

248908

Hom.:

AF XY:

0.00478

AC XY:

645

AN XY:

135032

show subpopulations

Gnomad AFR exome

AF:

0.000129

Gnomad AMR exome

AF:

0.000783

Gnomad ASJ exome

AF:

0.000895

Gnomad EAS exome

AF:

0.0000557

Gnomad SAS exome

AF:

0.0219

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00183

Gnomad OTH exome

AF:

0.00365

GnomAD4 exome

AF:

0.00225

AC:

3292

AN:

1461404

Hom.:

Cov.:

AF XY:

0.00287

AC XY:

2087

AN XY:

726988

show subpopulations

Gnomad4 AFR exome

AF:

0.000359

Gnomad4 AMR exome

AF:

0.000693

Gnomad4 ASJ exome

AF:

0.000842

Gnomad4 EAS exome

AF:

0.0000756

Gnomad4 SAS exome

AF:

0.0210

Gnomad4 FIN exome

AF:

0.0000749

Gnomad4 NFE exome

AF:

0.00110

Gnomad4 OTH exome

AF:

0.00268

GnomAD4 genome

AF:

0.00179

AC:

272

AN:

152244

Hom.:

Cov.:

AF XY:

0.00210

AC XY:

156

AN XY:

74434

show subpopulations

Gnomad4 AFR

AF:

0.000168

Gnomad4 AMR

AF:

0.00170

Gnomad4 ASJ

AF:

0.000864

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.0245

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00168

Gnomad4 OTH

AF:

0.00142

Alfa

AF:

0.00168

Hom.:

Bravo

AF:

0.00108

TwinsUK

AF:

0.000539

AC:

ALSPAC

AF:

0.00182

AC:

ESP6500AA

AF:

0.000526

AC:

ESP6500EA

AF:

0.00194

AC:

ExAC

AF:

0.00430

AC:

519

Asia WGS

AF:

0.00924

AC:

AN:

3478

EpiCase

AF:

0.00273

EpiControl

AF:

0.00273

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:20

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Benign:7

Benign, criteria provided, single submitter	clinical testing	GeneDx	Feb 08, 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. -
Likely benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jan 06, 2020	- -
Benign, criteria provided, single submitter	clinical testing	Athena Diagnostics	Nov 05, 2019	- -
Benign, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -
Benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Sep 01, 2015	- -
Benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Feb 25, 2015	p.Arg7253His in exon 85 of TTN: This variant is not expected to have clinical si gnificance because it has been identified in 2.3% (383/16508) of South Asian chr omosomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.o rg; dbSNP rs149855485). -

not provided

Uncertain:1Benign:5

Benign, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Mar 12, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Mar 17, 2014	- -
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	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -
Likely benign, no assertion criteria provided	clinical testing	Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)	-	- -
Likely benign, criteria provided, single submitter	research	Biesecker Lab/Clinical Genomics Section, National Institutes of Health	Jun 24, 2013	- -

Autosomal recessive limb-girdle muscular dystrophy type 2J

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. -

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

- -

Dilated cardiomyopathy 1G

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

Cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

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

May 30, 2019

- -

Early-onset myopathy with fatal cardiomyopathy

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

Myopathy, myofibrillar, 9, with early respiratory failure

Benign:1

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. -

Tibial muscular dystrophy

Benign:1

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. -

Primary dilated 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 28, 2017

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.22

BayesDel_addAF

Benign

-0.37

BayesDel_noAF

Benign

-0.29

CADD

Benign

DANN

Benign

0.87

Eigen

Uncertain

0.42

Eigen_PC

Uncertain

0.44

FATHMM_MKL

Uncertain

0.82

LIST_S2

Uncertain

0.87

D;D;.;D

MetaRNN

Benign

0.0059

T;T;T;T

MetaSVM

Benign

-0.42

PrimateAI

Uncertain

0.56

PROVEAN

Uncertain

-2.4

N;.;.;.

REVEL

Benign

0.19

Sift

Benign

0.043

D;.;.;.

Polyphen

0.99

.;.;D;D

Vest4

0.23

MVP

0.45

MPC

0.35

ClinPred

0.039

GERP RS

5.5

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