rs375009631

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4_StrongBP6

The NM_001267550.2(TTN):c.19715-4A>G variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000976 in 1,567,408 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00012 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000095 ( 0 hom. )

Consequence

TTN
NM_001267550.2 splice_region, splice_polypyrimidine_tract, intron

Scores

Splicing: ADA: 0.00003151

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:3

Conservation

PhyloP100: -1.28

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 -5 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.77).

BP6

Variant 2-178727867-T-C is Benign according to our data. Variant chr2-178727867-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 46660.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=2, Likely_benign=3}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.19715-4A>G		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000589042.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.19715-4A>G		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		5	NM_001267550.2	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.503-6637T>C		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.000118

AC:

AN:

152168

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000328

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000414

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.0000882

Gnomad OTH

AF:

0.000479

GnomAD3 exomes

AF:

0.0000619

AC:

AN:

209916

Hom.:

AF XY:

0.0000529

AC XY:

AN XY:

113400

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000111

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000464

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000805

Gnomad OTH exome

AF:

0.000205

GnomAD4 exome

AF:

0.0000954

AC:

135

AN:

1415240

Hom.:

Cov.:

AF XY:

0.0000986

AC XY:

AN XY:

700084

show subpopulations

Gnomad4 AFR exome

AF:

0.0000318

Gnomad4 AMR exome

AF:

0.0000819

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000261

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000110

Gnomad4 OTH exome

AF:

0.000120

GnomAD4 genome

AF:

0.000118

AC:

AN:

152168

Hom.:

Cov.:

AF XY:

0.000161

AC XY:

AN XY:

74332

show subpopulations

Gnomad4 AFR

AF:

0.0000724

Gnomad4 AMR

AF:

0.000328

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000414

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000882

Gnomad4 OTH

AF:

0.000479

Alfa

AF:

0.000116

Hom.:

Bravo

AF:

0.000185

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Nov 14, 2017	- -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jan 22, 2021	- -

Cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

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

Oct 13, 2021

- -

not specified

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Mar 19, 2012

15983-4A>G in intron 64 of TTN: This variant is not expected to have clinical si gnificance because it is not located within the splice consensus sequence. It ha s been identified in 1/6542 European American chromosomes from a broad populatio n by the NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS). 159 83-4A>G in intron 64 of TTN (allele frequency = 0.4%, 1/6542) ** -

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

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Jan 18, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.77

Cadd

Benign

0.27

Dann

Benign

0.62

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.000032

dbscSNV1_RF

Benign

0.068

SpliceAI score (max)

0.020

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