chr2-178719836-AAAG-A

Position:

chr2-178719836-AAAG-A

Variant summary

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

The NM_001267550.2(TTN):c.23660-7_23660-5del variant causes a splice region, splice polypyrimidine tract, intron change. The variant allele was found at a frequency of 0.000085 in 1,599,168 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000087 ( 0 hom. )

Consequence

TTN
NM_001267550.2 splice_region, splice_polypyrimidine_tract, intron

Scores

Not classified

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 5.93

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 0 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.23660-7_23660-5del		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000589042.5	NP_001254479.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.23660-7_23660-5del		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		5	NM_001267550.2	ENSP00000467141	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.503-14661_503-14659del		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.0000657

AC:

AN:

152136

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000414

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000882

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000801

AC:

AN:

237096

Hom.:

AF XY:

0.0000934

AC XY:

AN XY:

128534

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000308

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000571

Gnomad SAS exome

AF:

0.000214

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000102

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000871

AC:

126

AN:

1447032

Hom.:

AF XY:

0.0000947

AC XY:

AN XY:

717804

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000233

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000507

Gnomad4 SAS exome

AF:

0.000178

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000951

Gnomad4 OTH exome

AF:

0.0000503

GnomAD4 genome

AF:

0.0000657

AC:

AN:

152136

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74314

show subpopulations

Gnomad4 AFR

AF:

0.0000483

Gnomad4 AMR

AF:

0.00

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:

0.00

Bravo

AF:

0.0000453

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Feb 28, 2018	The c.22709-7_22709-5delCTT variant hasnot been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. Thisvariant results in the deletion of one of three CTT repeats in intron 79 and in silico splice prediction programs predicta significant reduction in the efficiency of the natural splice acceptor site. However, the NHLBI Exome SequencingProject reports that the c.22709-7_22709-5delCTT was observed 3/7,848 alleles from individuals of Europeanancestry, including one homozygous individual. Furthermore, truncating variants in the TTN gene have been reportedin approximately 3% of reported control alleles and this variant is not located in the A-band region of titin, where themajority of variants associated with DCM have been reported (Herman et al., 2012).Therefore, based on the currently available information, it is unclear whether this variant is pathogenic or rare benign. -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jul 14, 2016	- -

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

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 18, 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

Nov 03, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.080

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