rs772248060

Positions:

chr2-178802225-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 1P and 0B. PP2

The NM_001267550.2(TTN):c.208G>A(p.Val70Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000242 in 1,614,032 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. V70V) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000022 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:1

Conservation

PhyloP100: 7.91

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:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 1 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.208G>A	p.Val70Met	missense_variant	3/363	ENST00000589042.5
TTN	NM_133379.5 linkuse as main transcript	c.208G>A	p.Val70Met	missense_variant	3/46	ENST00000360870.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.208G>A	p.Val70Met	missense_variant	3/363	5	NM_001267550.2	P1
TTN	ENST00000360870.10 linkuse as main transcript	c.208G>A	p.Val70Met	missense_variant	3/46	5	NM_133379.5		Q8WZ42-6

Frequencies

GnomAD3 genomes

AF:

0.0000460

AC:

AN:

152174

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.0000882

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000477

AC:

AN:

251358

Hom.:

AF XY:

0.0000736

AC XY:

AN XY:

135836

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.000229

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000219

AC:

AN:

1461858

Hom.:

Cov.:

AF XY:

0.0000275

AC XY:

AN XY:

727238

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000171

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000460

AC:

AN:

152174

Hom.:

Cov.:

AF XY:

0.0000404

AC XY:

AN XY:

74334

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000882

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000329

Hom.:

Bravo

AF:

0.0000302

ExAC

AF:

0.0000412

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	Apr 23, 2018	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jun 05, 2018	- -

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

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 15, 2017

- -

Cardiovascular phenotype

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 29, 2020

This alteration is classified as likely 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

Pathogenic

0.64

BayesDel_addAF

Benign

-0.12

BayesDel_noAF

Benign

-0.12

CADD

Pathogenic

DANN

Benign

0.97

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.94

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

0.99

D;D;D;.;D;D;D;D

M_CAP

Benign

0.037

MetaRNN

Uncertain

0.52

D;D;D;D;D;D;D;D

MetaSVM

Uncertain

0.54

MutationTaster

Benign

0.96

D;D;D;D;D;D;D

PrimateAI

Uncertain

0.66

PROVEAN

Benign

-1.9

N;N;.;.;N;N;.;N

REVEL

Pathogenic

0.65

Sift

Uncertain

0.0080

D;D;.;.;D;D;.;D

Sift4G

Uncertain

0.0020

.;.;.;.;.;.;.;D

Polyphen

1.0

.;.;.;D;.;.;D;D

Vest4

0.42

MutPred

0.75

Gain of catalytic residue at V70 (P = 0.0689);Gain of catalytic residue at V70 (P = 0.0689);Gain of catalytic residue at V70 (P = 0.0689);Gain of catalytic residue at V70 (P = 0.0689);Gain of catalytic residue at V70 (P = 0.0689);Gain of catalytic residue at V70 (P = 0.0689);Gain of catalytic residue at V70 (P = 0.0689);Gain of catalytic residue at V70 (P = 0.0689);

MVP

0.72

MPC

0.45

ClinPred

0.16

GERP RS

5.7

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