rs200972189

Positions:

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 1P and 5B. PP2BP4_StrongBP6

The NM_001267550.2(TTN):c.25087G>T(p.Ala8363Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000142 in 1,607,364 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/18 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 0.00079 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000074 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:5

Conservation

PhyloP100: -0.310

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.

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=0.0064499676).

BP6

Variant 2-178717787-C-A is Benign according to our data. Variant chr2-178717787-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 46752.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=4}. Variant chr2-178717787-C-A is described in Lovd as [Benign].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.25087G>T	p.Ala8363Ser	missense_variant	87/363	ENST00000589042.5	NP_001254479.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.25087G>T	p.Ala8363Ser	missense_variant	87/363	5	NM_001267550.2	ENSP00000467141	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.503-16717C>A		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.000789

AC:

120

AN:

152084

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00258

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000655

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:

0.000957

GnomAD3 exomes

AF:

0.000206

AC:

AN:

242328

Hom.:

AF XY:

0.000144

AC XY:

AN XY:

131660

show subpopulations

Gnomad AFR exome

AF:

0.00257

Gnomad AMR exome

AF:

0.000326

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000742

AC:

108

AN:

1455162

Hom.:

Cov.:

AF XY:

0.0000608

AC XY:

AN XY:

723166

show subpopulations

Gnomad4 AFR exome

AF:

0.00230

Gnomad4 AMR exome

AF:

0.000318

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:

0.00000180

Gnomad4 OTH exome

AF:

0.000267

GnomAD4 genome

AF:

0.000788

AC:

120

AN:

152202

Hom.:

Cov.:

AF XY:

0.000739

AC XY:

AN XY:

74416

show subpopulations

Gnomad4 AFR

AF:

0.00258

Gnomad4 AMR

AF:

0.000654

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:

0.000947

Alfa

AF:

0.0000884

Hom.:

Bravo

AF:

0.000892

ESP6500AA

AF:

0.00298

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000215

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4Benign:5

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Uncertain:2Benign:2

Benign, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Mar 16, 2012	Variant classified as Uncertain Significance - Favor Benign. The Ala7119Ser vari ant in TTN has been identified in 0.2% (7/2996) of African American chromosomes from a broad population by the NHLBI Exome Sequencing Project (http://evs.gs.was hington.edu/EVS). Computational analyses (biochemical amino acid properties, con servation, AlignGVGD, PolyPhen2, and SIFT) do not provide strong support for or against an impact to the protein. While this frequency suggests that Ala7119Ser variant is more likely benign, it is too low to confidently rule out a disease c ausing role. Additional information is needed to fully assess its clinical signi ficance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Athena Diagnostics	Jun 20, 2017	- -

not provided

Uncertain:2Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jul 03, 2018	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Aug 26, 2013	- -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jun 24, 2020	- -

TTN-related disorder

Benign:1

Likely benign, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Jun 27, 2023

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

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

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 25, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.11

BayesDel_addAF

Benign

-0.36

BayesDel_noAF

Benign

-0.30

CADD

Benign

DANN

Benign

0.96

Eigen

Benign

-0.13

Eigen_PC

Benign

0.088

FATHMM_MKL

Benign

0.67

LIST_S2

Benign

0.69

T;T;.;T

M_CAP

Benign

0.0078

MetaRNN

Benign

0.0064

T;T;T;T

MetaSVM

Benign

-0.94

MutationTaster

Benign

1.0

D;D;D;N;N;N

PrimateAI

Benign

0.48

PROVEAN

Benign

-1.6

N;.;.;.

REVEL

Benign

0.22

Sift

Benign

0.35

T;.;.;.

Polyphen

0.020

.;.;B;B

Vest4

0.20

MVP

0.16

MPC

0.080

ClinPred

0.020

GERP RS

5.9

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.030

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