rs376870149

Variant summary

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

The NM_001267550.2(TTN):c.69853G>A(p.Glu23285Lys) variant causes a missense change. The variant allele was found at a frequency of 0.0000642 in 1,604,368 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 0.00019 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000051 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 6.12

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 where missense usually causes diseases, TTN

BP4

Computational evidence support a benign effect (MetaRNN=0.087809).

BP6

Variant 2-178576279-C-T is Benign according to our data. Variant chr2-178576279-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 178194.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.69853G>A	p.Glu23285Lys	missense_variant	326/363	ENST00000589042.5
TTN-AS1	NR_038272.1 linkuse as main transcript	n.2044-6293C>T		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.69853G>A	p.Glu23285Lys	missense_variant	326/363	5	NM_001267550.2	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.417-21317C>T		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.000197

AC:

AN:

152018

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000628

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000656

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000546

AC:

AN:

238236

Hom.:

AF XY:

0.0000387

AC XY:

AN XY:

129358

show subpopulations

Gnomad AFR exome

AF:

0.000396

Gnomad AMR exome

AF:

0.0000904

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000351

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000278

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000510

AC:

AN:

1452232

Hom.:

Cov.:

AF XY:

0.0000485

AC XY:

AN XY:

721826

show subpopulations

Gnomad4 AFR exome

AF:

0.000334

Gnomad4 AMR exome

AF:

0.0000923

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000253

Gnomad4 SAS exome

AF:

0.0000118

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000505

Gnomad4 OTH exome

AF:

0.0000167

GnomAD4 genome

AF:

0.000191

AC:

AN:

152136

Hom.:

Cov.:

AF XY:

0.000134

AC XY:

AN XY:

74362

show subpopulations

Gnomad4 AFR

AF:

0.000602

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000117

Hom.:

Bravo

AF:

0.000204

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.000522

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000911

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jun 12, 2013

The Glu20717Lys variant in TTN has not been reported in individuals with cardiom yopathy, but has been identified in 2/3830 African American chromosomes by the N HLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS/). Computational analyses (biochemical amino acid properties, conservation, AlignGVGD, and PolyP hen2) suggest that this variant may not impact the protein, though this informat ion is not predictive enough to rule out pathogenicity. Additional information i s needed to fully assess the clinical significance of the Glu20717Lys variant. -

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

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 11, 2017

- -

not provided

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

Oct 01, 2020

- -

Cardiovascular phenotype

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 19, 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

0.088

BayesDel_addAF

Benign

-0.29

BayesDel_noAF

Benign

-0.34

Cadd

Benign

Dann

Benign

0.77

Eigen

Benign

0.16

Eigen_PC

Benign

0.19

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.88

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

M_CAP

Benign

0.034

MetaRNN

Benign

0.088

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

MetaSVM

Benign

-0.75

MutationTaster

Benign

1.0

D;D;D;D;D;D

PrimateAI

Benign

0.41

PROVEAN

Uncertain

-2.6

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

REVEL

Benign

0.23

Sift

Benign

0.073

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

Polyphen

0.61

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

Vest4

0.38

MVP

0.24

MPC

0.14

ClinPred

0.043

GERP RS

5.9

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