2-178564605-C-T

Variant names:

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BP4_ModerateBP6_Moderate

The NM_001267550.2(TTN):c.81527G>A(p.Arg27176His) variant causes a missense change. The variant allele was found at a frequency of 0.00000744 in 1,613,326 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R27176L) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: 5.28

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 -4 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.1674909).

BP6

Variant 2-178564605-C-T is Benign according to our data. Variant chr2-178564605-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 2442822.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.81527G>A	p.Arg27176His	missense_variant	Exon 326 of 363	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 link	c.81527G>A	p.Arg27176His	missense_variant	Exon 326 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152078

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:

0.000193

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000363

AC:

AN:

248196

Hom.:

AF XY:

0.0000297

AC XY:

AN XY:

134650

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000449

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.000166

GnomAD4 exome

AF:

0.00000616

AC:

AN:

1461248

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

726902

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000505

Gnomad4 SAS exome

AF:

0.0000348

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000360

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152078

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74264

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000416

ExAC

AF:

0.0000248

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.000109

EpiControl

AF:

0.00

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Cardiomyopathy

Benign:1

Mar 16, 2022

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

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.10

BayesDel_addAF

Benign

-0.31

BayesDel_noAF

Benign

-0.35

CADD

Benign

DANN

Benign

0.88

Eigen

Pathogenic

0.70

Eigen_PC

Pathogenic

0.72

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.95

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

M_CAP

Benign

0.026

MetaRNN

Benign

0.17

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

MetaSVM

Benign

-0.55

MutationAssessor

Benign

1.8

.;.;.;L;.;.;L

PrimateAI

Uncertain

0.56

PROVEAN

Uncertain

-3.2

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

REVEL

Benign

0.24

Sift

Benign

0.034

D;D;.;.;T;D;.

Polyphen

0.99

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

Vest4

0.39

MutPred

0.45

.;.;.;Loss of loop (P = 0.1242);.;.;Loss of loop (P = 0.1242);

MVP

0.30

MPC

0.37

ClinPred

0.30

GERP RS

5.9

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

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