rs149059189

Variant summary

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

The NM_001267550.2(TTN):c.41488G>A(p.Val13830Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000781 in 1,613,250 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. V13830V) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00040 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000044 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:6

Conservation

PhyloP100: 0.0690

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 where missense usually causes diseases, TTN

BP4

Computational evidence support a benign effect (MetaRNN=0.011718988).

BP6

Variant 2-178636083-C-T is Benign according to our data. Variant chr2-178636083-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 202620.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=5, Uncertain_significance=2, Benign=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.41488G>A	p.Val13830Ile	missense_variant	226/363	ENST00000589042.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.41488G>A	p.Val13830Ile	missense_variant	226/363	5	NM_001267550.2	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.502+38402C>T		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.000401

AC:

AN:

152008

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00126

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000194

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000736

Gnomad OTH

AF:

0.000479

GnomAD3 exomes

AF:

0.000105

AC:

AN:

248378

Hom.:

AF XY:

0.0000891

AC XY:

AN XY:

134738

show subpopulations

Gnomad AFR exome

AF:

0.00123

Gnomad AMR exome

AF:

0.000116

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:

0.00

GnomAD4 exome

AF:

0.0000445

AC:

AN:

1461124

Hom.:

Cov.:

AF XY:

0.0000358

AC XY:

AN XY:

726842

show subpopulations

Gnomad4 AFR exome

AF:

0.00129

Gnomad4 AMR exome

AF:

0.0000671

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000108

Gnomad4 OTH exome

AF:

0.0000994

GnomAD4 genome

AF:

0.000401

AC:

AN:

152126

Hom.:

Cov.:

AF XY:

0.000417

AC XY:

AN XY:

74368

show subpopulations

Gnomad4 AFR

AF:

0.00125

Gnomad4 AMR

AF:

0.000131

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000194

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000736

Gnomad4 OTH

AF:

0.000474

Alfa

AF:

0.000644

Hom.:

Bravo

AF:

0.000416

ESP6500AA

AF:

0.00123

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000140

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:6

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1Benign:3

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jun 02, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jun 11, 2015	- -
Likely benign, criteria provided, single submitter	clinical testing	Athena Diagnostics	Oct 30, 2018	- -
Likely benign, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Apr 04, 2023	- -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 25, 2013

The p.V11262I variant (also known as c.33784G>A) is located in coding exon 174 of the TTN gene. This alteration results from a G to A substitution at nucleotide position 33784. The valine at codon 11262 is replaced by isoleucine, an amino acid with highly similar properties. Ã¢â‚¬â€¹ Ã¢â‚¬â€¹This variant was previously reported in the SNPDatabase as rs149059189. Based on data from the NHLBI Exome Sequencing Project (ESP), the A-allele has an overall frequency of approximately 0.04% (5/12,442), having been observed in 0.12% (5/4078) of African American alleles, and not observed in 8364 European American alleles studied. Based on data from the 1000 Genomes Project, the A-allele has an overall frequency of approximately 0.05% (1/2184). The highest observed frequency was 0.52% (1/194) Luhya chromosomes studied. This amino acid position is poorly conserved in available vertebrate species. This variant is predicted to be benign by PolyPhen in silico analyses. Since supporting evidence is limited at this time, the clinical significance of p.V11262I remains unclear. -

not specified

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Nov 20, 2023

Variant summary: TTN c.33784G>A (p.Val11262Ile) results in a conservative amino acid change located in the I-band region of the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.0001 in 248378 control chromosomes, predominantly at a frequency of 0.0012 within the African or African-American subpopulation in the gnomAD database. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 3-fold of the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Dilated Cardiomyopathy phenotype (0.00039), strongly suggesting that the variant is a benign polymorphism found primarily in populations of African or African-American origin. To our knowledge, no occurrence of c.33784G>A in individuals affected with Dilated Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. Six submitters have reported clinical-significance assessments for this variant to ClinVar after 2014. Multiple submitters reported the variant with conflicting assessments (benign, n = 1; likely benign, n = 3; uncertain significance, n = 2). Based on the evidence outlined above, the variant was classified as likely benign. -

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

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Jan 31, 2024

- -

Cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

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

May 08, 2020

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.070

BayesDel_addAF

Benign

-0.62

BayesDel_noAF

Benign

-0.67

Cadd

Benign

2.9

Dann

Benign

0.80

Eigen

Benign

-1.1

Eigen_PC

Benign

-1.1

FATHMM_MKL

Benign

0.037

LIST_S2

Benign

0.68

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

M_CAP

Benign

0.010

MetaRNN

Benign

0.012

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

MetaSVM

Benign

-0.96

MutationTaster

Benign

1.0

N;N;N;N;N;N

PrimateAI

Benign

0.38

PROVEAN

Benign

-0.48

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

REVEL

Benign

0.030

Sift

Benign

0.38

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

Polyphen

0.019

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

Vest4

0.11

MVP

0.072

MPC

0.070

ClinPred

0.0028

GERP RS

-0.079

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