rs199583938

Variant summary

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

The NM_001267550.2(TTN):c.67808C>T(p.Ala22603Val) variant causes a missense change. The variant allele was found at a frequency of 0.0000397 in 1,613,328 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 11/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. A22603A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000099 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000034 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:7

Conservation

PhyloP100: 5.30

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:

(HGNC:):

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 where missense usually causes diseases, TTN

BP4

Computational evidence support a benign effect (MetaRNN=0.19436324).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.67808C>T	p.Ala22603Val	missense_variant	320/363	ENST00000589042.5
TTN-AS1	NR_038272.1 linkuse as main transcript	n.2044-3350G>A		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris
TTN	ENST00000589042.5 linkuse as main transcript	c.67808C>T	p.Ala22603Val	missense_variant	320/363	5	NM_001267550.2	P1
	ENST00000603521.1 linkuse as main transcript	n.433G>A		non_coding_transcript_exon_variant	1/1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.417-18374G>A		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.0000987

AC:

AN:

152028

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000217

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000194

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.0000943

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000362

AC:

AN:

248658

Hom.:

AF XY:

0.0000371

AC XY:

AN XY:

134880

show subpopulations

Gnomad AFR exome

AF:

0.000129

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000112

Gnomad SAS exome

AF:

0.0000981

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000178

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000335

AC:

AN:

1461300

Hom.:

Cov.:

AF XY:

0.0000358

AC XY:

AN XY:

726932

show subpopulations

Gnomad4 AFR exome

AF:

0.000149

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000757

Gnomad4 SAS exome

AF:

0.000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000270

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000987

AC:

AN:

152028

Hom.:

Cov.:

AF XY:

0.0000539

AC XY:

AN XY:

74236

show subpopulations

Gnomad4 AFR

AF:

0.000217

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000194

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.0000943

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000832

Hom.:

Bravo

AF:

0.0000529

ExAC

AF:

0.0000414

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Jul 10, 2014	The Ala20035Val variant in TTN has not been previously reported in individuals w ith cardiomyopathy, but has been identified in 1/594 of European chromosomes by the ClinSeq Project (dbSNP rs199583938). Computational prediction tools and cons ervation analysis do not provide strong support for or against an impact to the protein. In summary, the clinical significance of the Ala20035Val variant is unc ertain. -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Jan 10, 2017	Missense variants in the TTN gene are considered 'unclassified' if they are not previously reported in the literature and do not have >1% frequency in the population to be considered a polymorphism. Research indicates that truncating mutations in the TTN gene are expected to account for approximately 25% of familial and 18% of sporadic idiopathic DCM; however, truncating variants in the TTN gene have been reported in approximately 3% of reported control alleles. There has been little investigation into non-truncating variants. (Herman D et al. Truncations of titin causing dilated cardiomyopathy. N Eng J Med 366:619-628, 2012) The variant is found in CARDIOMYOPATHY panel(s). -

not provided

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jun 02, 2018	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Jan 03, 2023	- -

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

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 10, 2016

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1838244:Tibial muscular dystrophy;C1858763:Dilated cardiomyopathy 1G;C1861065:Hypertrophic cardiomyopathy 9;C1863599:Myopathy, myofibrillar, 9, with early respiratory failure;C2673677:Early-onset myopathy with fatal cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Jul 30, 2021

- -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 05, 2020

The p.A13538V variant (also known as c.40613C>T), located in coding exon 147 of the TTN gene, results from a C to T substitution at nucleotide position 40613. The alanine at codon 13538 is replaced by valine, an amino acid with similar properties. This amino acid position is not well 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 alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.12

BayesDel_addAF

Benign

-0.32

BayesDel_noAF

Benign

-0.46

Cadd

Benign

Dann

Benign

0.95

Eigen

Uncertain

0.49

Eigen_PC

Uncertain

0.59

FATHMM_MKL

Uncertain

0.91

LIST_S2

Uncertain

0.92

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

M_CAP

Benign

0.025

MetaRNN

Benign

0.19

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

MetaSVM

Benign

-0.98

MutationTaster

Benign

0.99

D;D;D;D;D;D

PrimateAI

Uncertain

0.58

PROVEAN

Uncertain

-2.6

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

REVEL

Benign

0.16

Sift

Benign

0.043

D;T;.;.;T;T;.

Polyphen

0.96

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

Vest4

0.29

MutPred

0.47

.;.;.;Loss of glycosylation at S20961 (P = 0.1229);.;.;Loss of glycosylation at S20961 (P = 0.1229);

MVP

0.32

MPC

0.19

ClinPred

0.11

GERP RS

6.0

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