2-178663290-T-C

Position:

chr2-178663290-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.36676A>G(p.Lys12226Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00303 in 1,564,470 control chromosomes in the GnomAD database, including 419 homozygotes. In-silico tool predicts a benign outcome for this variant. 11/14 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0015 ( 2 hom., cov: 26)

Exomes 𝑓: 0.0032 ( 417 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:12

Conservation

PhyloP100: 0.428

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 (HGNC:):

TTN 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=0.008118629).

BP6

Variant 2-178663290-T-C is Benign according to our data. Variant chr2-178663290-T-C is described in ClinVar as [Likely_benign]. Clinvar id is 192172.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178663290-T-C is described in Lovd as [Likely_benign].

BS1

Variant frequency is greater than expected in population nfe. gnomad4_exome allele frequency = 0.00319 (4536/1421022) while in subpopulation NFE AF= 0.00393 (4292/1091434). AF 95% confidence interval is 0.00383. There are 417 homozygotes in gnomad4_exome. There are 2120 alleles in male gnomad4_exome subpopulation. Median coverage is 33. This position pass quality control queck.

BS2

High Homozygotes in GnomAd4 at 2 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.36676A>G	p.Lys12226Glu	missense_variant	173/363	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.36676A>G	p.Lys12226Glu	missense_variant	173/363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.00148

AC:

212

AN:

143358

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000682

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000721

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.000100

Gnomad MID

AF:

0.00318

Gnomad NFE

AF:

0.00259

Gnomad OTH

AF:

0.00102

GnomAD3 exomes

AF:

0.00165

AC:

376

AN:

228360

Hom.:

AF XY:

0.00159

AC XY:

197

AN XY:

123608

show subpopulations

Gnomad AFR exome

AF:

0.000491

Gnomad AMR exome

AF:

0.00142

Gnomad ASJ exome

AF:

0.000106

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.000436

Gnomad NFE exome

AF:

0.00284

Gnomad OTH exome

AF:

0.00139

GnomAD4 exome

AF:

0.00319

AC:

4536

AN:

1421022

Hom.:

417

Cov.:

AF XY:

0.00300

AC XY:

2120

AN XY:

706362

show subpopulations

Gnomad4 AFR exome

AF:

0.000408

Gnomad4 AMR exome

AF:

0.00109

Gnomad4 ASJ exome

AF:

0.000118

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000380

Gnomad4 FIN exome

AF:

0.000378

Gnomad4 NFE exome

AF:

0.00393

Gnomad4 OTH exome

AF:

0.00273

GnomAD4 genome

AF:

0.00148

AC:

212

AN:

143448

Hom.:

Cov.:

AF XY:

0.00138

AC XY:

AN XY:

69422

show subpopulations

Gnomad4 AFR

AF:

0.000680

Gnomad4 AMR

AF:

0.000720

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.000100

Gnomad4 NFE

AF:

0.00259

Gnomad4 OTH

AF:

0.00101

Alfa

AF:

0.00179

Hom.:

Bravo

AF:

0.00148

ESP6500AA

AF:

0.00117

AC:

ESP6500EA

AF:

0.00253

AC:

ExAC

AF:

0.00170

AC:

200

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:12

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Benign:5

Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jul 01, 2024	TTN: BP4, BS2 -
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	research	Biesecker Lab/Clinical Genomics Section, National Institutes of Health	Jun 24, 2013	- -
Likely benign, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -

not specified

Benign:1

Benign, no assertion criteria provided

clinical testing

Genome Diagnostics Laboratory, University Medical Center Utrecht

- -

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

Dec 06, 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

Mar 27, 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

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Benign

-0.38

BayesDel_noAF

Benign

-0.45

CADD

Benign

DANN

Benign

0.75

Eigen

Benign

-0.27

Eigen_PC

Benign

-0.41

FATHMM_MKL

Benign

0.22

LIST_S2

Benign

0.35

M_CAP

Benign

0.049

MetaRNN

Benign

0.0081

MetaSVM

Benign

-0.92

Vest4

0.16

MVP

0.26

MPC

0.42

ClinPred

0.013

GERP RS

4.4

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