rs374656017

Positions:

chr2-178581678-C-T

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 1P and 2B. PP2BP4_Moderate

The NM_001267550.2(TTN):c.66590G>A(p.Arg22197Gln) variant causes a missense change. The variant allele was found at a frequency of 0.0000639 in 1,612,470 control chromosomes in the GnomAD database, including 1 homozygotes. 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R22197W) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00016 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000054 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:1

Conservation

PhyloP100: 3.92

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 -1 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=0.14143303).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.66590G>A	p.Arg22197Gln	missense_variant	316/363	ENST00000589042.5	NP_001254479.2
TTN-AS1	NR_038272.1 linkuse as main transcript	n.2044-894C>T		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.66590G>A	p.Arg22197Gln	missense_variant	316/363	5	NM_001267550.2	ENSP00000467141	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.417-15918C>T		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.000158

AC:

AN:

152012

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000386

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000776

Gnomad SAS

AF:

0.000208

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.000955

GnomAD3 exomes

AF:

0.0000971

AC:

AN:

247274

Hom.:

AF XY:

0.0000745

AC XY:

AN XY:

134182

show subpopulations

Gnomad AFR exome

AF:

0.000389

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000737

Gnomad SAS exome

AF:

0.0000328

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000179

Gnomad OTH exome

AF:

0.000335

GnomAD4 exome

AF:

0.0000541

AC:

AN:

1460340

Hom.:

Cov.:

AF XY:

0.0000482

AC XY:

AN XY:

726420

show subpopulations

Gnomad4 AFR exome

AF:

0.000150

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000634

Gnomad4 SAS exome

AF:

0.0000580

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000261

Gnomad4 OTH exome

AF:

0.000249

GnomAD4 genome

AF:

0.000158

AC:

AN:

152130

Hom.:

Cov.:

AF XY:

0.000215

AC XY:

AN XY:

74354

show subpopulations

Gnomad4 AFR

AF:

0.000385

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000778

Gnomad4 SAS

AF:

0.000208

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.000945

Alfa

AF:

0.0000763

Hom.:

Bravo

AF:

0.000147

ESP6500AA

AF:

0.000253

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000745

AC:

Asia WGS

AF:

0.00115

AC:

AN:

3478

EpiCase

AF:

0.000109

EpiControl

AF:

0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:3Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Apr 27, 2023	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Dec 09, 2014	- -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Feb 07, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Dec 01, 2021	- -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Apr 03, 2013

The Arg19629Gln variant in TTN has not been reported in the literature nor previ ously identified by our laboratory. This variant has been identified in 1/3960 A frican American chromosomes by the NHLBI Exome Sequencing Project (http://evs.gs .washington.edu/EVS/). Computational analyses (biochemical amino acid properties , conservation, AlignGVGD, PolyPhen2, and SIFT) do not provide strong support fo r or against an impact to the protein. Additional information is needed to fully assess the clinical significance of this variant. -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 20, 2015

The p.R13132Q variant (also known as c.39395G>A), located in coding exon 143 of the TTN gene, results from a G to A substitution at nucleotide position 39395. The arginine at codon 13132 is replaced by glutamine, an amino acid with highly similar properties. This variant was previously reported in the SNPDatabase as rs374656017. Based on data from the NHLBI Exome Sequencing Project (ESP), the A allele has an overall frequency of approximately 0.01% (1/12236) total alleles studied, having been observed in 0.03% (1/3960) African American alleles. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.15

BayesDel_addAF

Benign

-0.34

BayesDel_noAF

Benign

-0.35

CADD

Benign

DANN

Benign

0.96

Eigen

Uncertain

0.53

Eigen_PC

Uncertain

0.52

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.93

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

M_CAP

Benign

0.016

MetaRNN

Benign

0.14

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

MetaSVM

Benign

-0.56

MutationAssessor

Benign

0.28

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

MutationTaster

Benign

1.0

D;D;D;D;D;D

PrimateAI

Uncertain

0.60

PROVEAN

Uncertain

-2.7

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

REVEL

Benign

0.21

Sift

Benign

0.23

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

Polyphen

1.0

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

Vest4

0.49

MVP

0.25

MPC

0.46

ClinPred

0.078

GERP RS

4.5

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