rs75458912

Variant summary

Our verdict is Benign. Variant got -11 ACMG points: 1P and 12B. PP2BP4_StrongBP6_Very_Strong

The NM_001267550.2(TTN):c.62149A>G(p.Arg20717Gly) variant causes a missense change. The variant allele was found at a frequency of 0.000104 in 1,613,438 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. R20717R) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000092 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00010 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:8

Conservation

PhyloP100: 5.07

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 -11 ACMG points.

PP2

Missense variant where missense usually causes diseases, TTN

BP4

Computational evidence support a benign effect (MetaRNN=0.014564544).

BP6

Variant 2-178589576-T-C is Benign according to our data. Variant chr2-178589576-T-C is described in ClinVar as [Likely_benign]. Clinvar id is 467346.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178589576-T-C is described in Lovd as [Likely_benign].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.62149A>G	p.Arg20717Gly	missense_variant	304/363	ENST00000589042.5
TTN-AS1	NR_038272.1 linkuse as main transcript	n.3189-1563T>C		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.62149A>G	p.Arg20717Gly	missense_variant	304/363	5	NM_001267550.2	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.417-8020T>C		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.0000855

AC:

AN:

152112

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000656

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00213

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000266

AC:

AN:

247740

Hom.:

AF XY:

0.000223

AC XY:

AN XY:

134340

show subpopulations

Gnomad AFR exome

AF:

0.0000646

Gnomad AMR exome

AF:

0.0000581

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00353

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000105

AC:

153

AN:

1461208

Hom.:

Cov.:

AF XY:

0.000102

AC XY:

AN XY:

726882

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000447

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00359

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000450

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000920

AC:

AN:

152230

Hom.:

Cov.:

AF XY:

0.0000672

AC XY:

AN XY:

74430

show subpopulations

Gnomad4 AFR

AF:

0.0000240

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00233

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000325

Hom.:

Bravo

AF:

0.000166

ExAC

AF:

0.000224

AC:

Asia WGS

AF:

0.000867

AC:

AN:

3476

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Benign:2

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jun 28, 2019	- -
Likely benign, criteria provided, single submitter	clinical testing	Athena Diagnostics	Mar 28, 2018	- -

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

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Jan 29, 2024

- -

Cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

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

Jan 31, 2018

- -

Early-onset myopathy with fatal cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

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

0.77

BayesDel_addAF

Benign

-0.30

BayesDel_noAF

Benign

-0.20

Cadd

Benign

Dann

Benign

0.89

Eigen

Uncertain

0.64

Eigen_PC

Pathogenic

0.68

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Benign

0.84

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

M_CAP

Benign

0.031

MetaRNN

Benign

0.015

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

MetaSVM

Benign

-0.59

MutationTaster

Benign

1.0

D;D;D;D;D;D

PrimateAI

Uncertain

0.52

PROVEAN

Pathogenic

-4.7

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

REVEL

Uncertain

0.33

Sift

Uncertain

0.019

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

Polyphen

0.98

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

Vest4

0.50

MVP

0.47

MPC

0.37

ClinPred

0.096

GERP RS

6.2

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