2-178632421-GAA-GAAA

Position:

chr2-178632421-GAA-GAAA

Variant summary

Our verdict is Benign. Variant got -8 ACMG points: 0P and 8B. BP6_Very_Strong

The NM_001267550.2(TTN):c.43481-9dupT variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000121 in 1,567,598 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.00011 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00012 ( 1 hom. )

Consequence

TTN
NM_001267550.2 intron

Scores

Not classified

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:7

Conservation

PhyloP100: -0.257

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 Benign. Variant got -8 ACMG points.

BP6

Variant 2-178632421-G-GA is Benign according to our data. Variant chr2-178632421-G-GA is described in ClinVar as [Likely_benign]. Clinvar id is 179050.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.43481-9dupT		intron_variant		ENST00000589042.5	NP_001254479.2	A0A0A0MTS7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 link	c.43481-9dupT		intron_variant		5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.000106

AC:

AN:

150936

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000122

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000132

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:

0.000133

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.000123

AC:

174

AN:

1416662

Hom.:

Cov.:

AF XY:

0.000144

AC XY:

101

AN XY:

701994

show subpopulations

Gnomad4 AFR exome

AF:

0.0000647

Gnomad4 AMR exome

AF:

0.0000909

Gnomad4 ASJ exome

AF:

0.000289

Gnomad4 EAS exome

AF:

0.0000257

Gnomad4 SAS exome

AF:

0.000166

Gnomad4 FIN exome

AF:

0.0000191

Gnomad4 NFE exome

AF:

0.000120

Gnomad4 OTH exome

AF:

0.000137

GnomAD4 genome

AF:

0.000106

AC:

AN:

150936

Hom.:

Cov.:

AF XY:

0.0000680

AC XY:

AN XY:

73568

show subpopulations

Gnomad4 AFR

AF:

0.000122

Gnomad4 AMR

AF:

0.000132

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000133

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.000106

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:1

Benign, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jan 22, 2014

35777-9_35777-8insT in intron 185 of TTN: This variant is not expected to have clinical significance because it does not alter the splice consensus sequence an d has been identified in 0.5% (57/11282) of European American and African Americ an chromosomes by the NHLBI Exome Sequencing Project (http://evs.gs.washington.e du/EVS/). 35777-9_35777-8insT in intron 185 of TTN (allele frequency = 0.5%, 5 7/11282) ** -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

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

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 29, 2024

- -

Early-onset myopathy with fatal cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

not provided

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

Dec 18, 2020

- -

Tibial muscular dystrophy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Myopathy, myofibrillar, 9, with early respiratory failure

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

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