2-178561092-A-G

Position:

chr2-178561092-A-G

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4_StrongBP6

The NM_001267550.2(TTN):c.85040T>C(p.Ile28347Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000204 in 1,613,780 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/19 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 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000022 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:2

Conservation

PhyloP100: 8.08

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 -5 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.048012048).

BP6

Variant 2-178561092-A-G is Benign according to our data. Variant chr2-178561092-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 47443.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=4, Likely_benign=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.85040T>C	p.Ile28347Thr	missense_variant	326/363	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 link	c.85040T>C	p.Ile28347Thr	missense_variant	326/363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152178

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000161

AC:

AN:

248576

Hom.:

AF XY:

0.0000148

AC XY:

AN XY:

134836

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

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:

0.0000267

Gnomad OTH exome

AF:

0.000166

GnomAD4 exome

AF:

0.0000219

AC:

AN:

1461602

Hom.:

Cov.:

AF XY:

0.0000206

AC XY:

AN XY:

727098

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000288

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152178

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74338

show subpopulations

Gnomad4 AFR

AF:

0.00

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000189

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Dec 10, 2014	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Feb 27, 2023	- -

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

Mar 17, 2017

- -

Cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

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

May 14, 2020

- -

not specified

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jan 26, 2016

p.Ile25779Thr in exon 275 of TTN: This variant is not expected to have clinical significance due to a lack of conservation across species, including mammals. Of note, several mammals and evolutionarily distant species have a threonine (Thr) at this position despite high nearby amino acid conservation. In addition, com putational prediction tools suggest it may not impact the protein. It has been i dentified in 2/66690 European chromosomes by the Exome Aggregation Consortium (E xAC, http://exac.broadinstitute.org; dbSNP rs397517731). -

Cardiovascular phenotype

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 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

Benign

0.050

BayesDel_addAF

Benign

-0.26

BayesDel_noAF

Benign

-0.55

CADD

Benign

DANN

Benign

0.79

Eigen

Benign

-0.47

Eigen_PC

Benign

-0.20

FATHMM_MKL

Benign

0.28

LIST_S2

Benign

0.73

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

M_CAP

Benign

0.032

MetaRNN

Benign

0.048

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

MetaSVM

Benign

-1.0

MutationAssessor

Benign

-1.5

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

PrimateAI

Uncertain

0.52

PROVEAN

Benign

2.7

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

REVEL

Benign

0.15

Sift

Benign

1.0

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

Polyphen

0.0

.;.;.;B;.;.;B

Vest4

0.13

MutPred

0.44

.;.;.;Loss of stability (P = 0.0149);.;.;Loss of stability (P = 0.0149);

MVP

0.40

MPC

0.11

ClinPred

0.084

GERP RS

4.0

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