rs66839174

Positions:

chr2-178733443-C-T

Variant summary

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

The NM_001267550.2(TTN):c.15850G>A(p.Val5284Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000651 in 1,613,824 control chromosomes in the GnomAD database, including 7 homozygotes. In-silico tool predicts a benign outcome for this variant. 10/17 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0037 ( 5 hom., cov: 33)

Exomes 𝑓: 0.00034 ( 2 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:14

Conservation

PhyloP100: 3.19

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=0.0072422326).

BP6

Variant 2-178733443-C-T is Benign according to our data. Variant chr2-178733443-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 46608.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178733443-C-T is described in Lovd as [Benign].

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00365 (556/152270) while in subpopulation AFR AF= 0.0124 (514/41562). AF 95% confidence interval is 0.0115. There are 5 homozygotes in gnomad4. There are 262 alleles in male gnomad4 subpopulation. Median coverage is 33. 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	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.15850G>A	p.Val5284Met	missense_variant	54/363	ENST00000589042.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.15850G>A	p.Val5284Met	missense_variant	54/363	5	NM_001267550.2	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.503-1061C>T		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.00363

AC:

553

AN:

152152

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0123

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00242

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00239

GnomAD3 exomes

AF:

0.000873

AC:

217

AN:

248552

Hom.:

AF XY:

0.000631

AC XY:

AN XY:

134792

show subpopulations

Gnomad AFR exome

AF:

0.0125

Gnomad AMR exome

AF:

0.000638

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.000332

GnomAD4 exome

AF:

0.000339

AC:

495

AN:

1461554

Hom.:

Cov.:

AF XY:

0.000276

AC XY:

201

AN XY:

727050

show subpopulations

Gnomad4 AFR exome

AF:

0.0122

Gnomad4 AMR exome

AF:

0.000738

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000270

Gnomad4 OTH exome

AF:

0.000779

GnomAD4 genome

AF:

0.00365

AC:

556

AN:

152270

Hom.:

Cov.:

AF XY:

0.00352

AC XY:

262

AN XY:

74440

show subpopulations

Gnomad4 AFR

AF:

0.0124

Gnomad4 AMR

AF:

0.00242

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00237

Alfa

AF:

0.000511

Hom.:

Bravo

AF:

0.00444

ESP6500AA

AF:

0.0110

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.00108

AC:

131

Asia WGS

AF:

0.00144

AC:

AN:

3478

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:14

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:8

Benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Nov 09, 2015	p.Val4040Met in exon 51 of TTN: This variant is not expected to have clinical si gnificance because it has been identified in 1.2% (121/9780) of African chromoso mes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; d bSNP rs66839174). -
Likely benign, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Aug 14, 2014	- -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Jun 11, 2015	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, no assertion criteria provided	clinical testing	Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)	-	- -
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	Mar 27, 2023	- -
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	Clinical Genetics, Academic Medical Center	-	- -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G

Benign:1

Benign, criteria provided, single submitter

clinical testing

Invitae

Jan 31, 2024

- -

Early-onset myopathy with fatal cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

not provided

Benign:1

Benign, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Jul 01, 2023

TTN: BS1, BS2 -

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

AlphaMissense

Pathogenic

0.68

BayesDel_addAF

Benign

-0.33

BayesDel_noAF

Benign

-0.23

CADD

Benign

DANN

Benign

0.94

Eigen

Pathogenic

0.87

Eigen_PC

Pathogenic

0.80

FATHMM_MKL

Uncertain

0.88

LIST_S2

Benign

0.85

T;D;.;D

MetaRNN

Benign

0.0072

T;T;T;T

MetaSVM

Uncertain

0.47

MutationTaster

Benign

1.0

D;D;D;N;N;N

PrimateAI

Uncertain

0.64

PROVEAN

Benign

-1.8

N;.;.;.

REVEL

Uncertain

0.46

Sift

Benign

0.030

D;.;.;.

Polyphen

1.0

.;.;D;D

Vest4

0.17

MVP

0.72

MPC

0.44

ClinPred

0.039

GERP RS

5.9

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