rs761974222

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PVS1_Strong

The NM_133379.5(TTN):c.12109C>T(p.Gln4037Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000242 in 1,613,004 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000040 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

TTN
NM_133379.5 stop_gained

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 0.385

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 Uncertain_significance. Variant got 4 ACMG points.

PVS1

Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.28 CDS is truncated, and there are 1 pathogenic variants in the truncated region.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_133379.5 linkuse as main transcript	c.12109C>T	p.Gln4037Ter	stop_gained	46/46	ENST00000360870.10
TTN	NM_001267550.2 linkuse as main transcript	c.11311+2833C>T		intron_variant		ENST00000589042.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000360870.10 linkuse as main transcript	c.12109C>T	p.Gln4037Ter	stop_gained	46/46	5	NM_133379.5		Q8WZ42-6
TTN	ENST00000589042.5 linkuse as main transcript	c.11311+2833C>T		intron_variant		5	NM_001267550.2	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.1224-5975G>A		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.0000395

AC:

AN:

151808

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000263

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:

0.0000295

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000199

AC:

AN:

250862

Hom.:

AF XY:

0.00000738

AC XY:

AN XY:

135580

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000290

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:

0.0000353

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000226

AC:

AN:

1461196

Hom.:

Cov.:

AF XY:

0.0000193

AC XY:

AN XY:

726908

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000224

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:

0.0000279

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000395

AC:

AN:

151808

Hom.:

Cov.:

AF XY:

0.0000809

AC XY:

AN XY:

74150

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000263

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000295

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000132

Hom.:

Bravo

AF:

0.0000340

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.0000546

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

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

Jan 25, 2019

Variant classified as Uncertain Significance - Favor Benign. The p.Gln4037X variant in TTN has not been previously reported in individuals with cardiomyopathy, but has been identified in 1/66612 European chromosomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org). This variant is located in the last exon of an alternative transcript (Novex-3) and is expected to result in a truncated protein. Although truncating variants in the TTN gene are common in individuals with DCM (Herman 2012), the function of the Novex-3 transcript is unclear. In summary, the clinical significance of the p.Gln4037X variant is uncertain. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

AiLife Diagnostics, AiLife Diagnostics

Jan 03, 2022

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Benign

-0.48

BayesDel_noAF

Benign

-0.84

Cadd

Benign

7.8

Dann

Benign

0.96

Eigen

Benign

-0.83

Eigen_PC

Benign

-0.93

FATHMM_MKL

Benign

0.14

MutationTaster

Benign

1.0

D;N;N;N;N;N;N

Vest4

0.35

GERP RS

1.3

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