rs751354601

Positions:

chr2-178581565-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 1P and 3B. PP2BP4_ModerateBP6

The NM_001267550.2(TTN):c.66703G>A(p.Val22235Ile) variant causes a missense change. The variant allele was found at a frequency of 0.0000955 in 1,612,272 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/19 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 0.00011 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000094 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:2

Conservation

PhyloP100: 4.96

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 Likely_benign. Variant got -2 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=0.21339011).

BP6

Variant 2-178581565-C-T is Benign according to our data. Variant chr2-178581565-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 467392.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=5, Likely_benign=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.66703G>A	p.Val22235Ile	missense_variant	316/363	ENST00000589042.5	NP_001254479.2
TTN-AS1	NR_038272.1 linkuse as main transcript	n.2044-1007C>T		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.66703G>A	p.Val22235Ile	missense_variant	316/363	5	NM_001267550.2	ENSP00000467141	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.417-16031C>T		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.000112

AC:

AN:

152068

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.0000883

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000109

AC:

AN:

247668

Hom.:

AF XY:

0.000127

AC XY:

AN XY:

134378

show subpopulations

Gnomad AFR exome

AF:

0.000323

Gnomad AMR exome

AF:

0.0000581

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000113

Gnomad SAS exome

AF:

0.000229

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000982

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000938

AC:

137

AN:

1460204

Hom.:

Cov.:

AF XY:

0.0000977

AC XY:

AN XY:

726356

show subpopulations

Gnomad4 AFR exome

AF:

0.000389

Gnomad4 AMR exome

AF:

0.0000672

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000759

Gnomad4 SAS exome

AF:

0.000139

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000900

Gnomad4 OTH exome

AF:

0.0000830

GnomAD4 genome

AF:

0.000112

AC:

AN:

152068

Hom.:

Cov.:

AF XY:

0.000135

AC XY:

AN XY:

74268

show subpopulations

Gnomad4 AFR

AF:

0.000241

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000883

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000165

Hom.:

Bravo

AF:

0.000136

ExAC

AF:

0.000141

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.000164

EpiControl

AF:

0.000297

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Jul 19, 2023	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Oct 02, 2017	- -

not specified

Uncertain:1Benign:1

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jan 05, 2018	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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Sep 23, 2024	Variant summary: TTN c.58999G>A (p.Val19667Ile) results in a conservative amino acid change located in the A band (cardiodb.org) of the encoded protein sequence. Three of four in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 9.6e-05 in 1612272 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in TTN causing Dilated Cardiomyopathy (9.6e-05 vs 0.00039), allowing no conclusion about variant significance. To our knowledge, no occurrence of c.58999G>A in individuals affected with Dilated Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 467392). Based on the evidence outlined above, the variant was classified as uncertain significance. -

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

Nov 04, 2017

- -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 05, 2019

The p.V13170I variant (also known as c.39508G>A), located in coding exon 143 of the TTN gene, results from a G to A substitution at nucleotide position 39508. The valine at codon 13170 is replaced by isoleucine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Cardiomyopathy

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

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

Nov 10, 2017

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.10

BayesDel_addAF

Benign

-0.27

BayesDel_noAF

Benign

-0.33

CADD

Benign

DANN

Benign

0.92

Eigen

Uncertain

0.28

Eigen_PC

Uncertain

0.32

FATHMM_MKL

Uncertain

0.96

LIST_S2

Benign

0.82

T;T;T;.;T;T;T

M_CAP

Benign

0.023

MetaRNN

Benign

0.21

T;T;T;T;T;T;T

MetaSVM

Benign

-0.75

MutationAssessor

Benign

0.67

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

MutationTaster

Benign

1.0

D;D;D;D;D;D

PrimateAI

Uncertain

0.58

PROVEAN

Benign

-0.83

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

REVEL

Benign

0.14

Sift

Benign

0.21

T;T;.;.;T;T;.

Polyphen

0.84

.;.;.;P;.;.;P

Vest4

0.35

MVP

0.54

MPC

0.17

ClinPred

0.035

GERP RS

4.5

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