chr2-178607082-CTTG-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PM4_Supporting

The NM_001267550.2(TTN):​c.53517_53519del​(p.Lys17840del) variant causes a inframe deletion change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

TTN
NM_001267550.2 inframe_deletion

Scores

Not classified

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.18
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-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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM4
Nonframeshift variant in NON repetitive region in NM_001267550.2. Strenght limited to Supporting due to length of the change: 1aa.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
TTNNM_001267550.2 linkuse as main transcriptc.53517_53519del p.Lys17840del inframe_deletion 278/363 ENST00000589042.5 NP_001254479.2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkuse as main transcriptc.53517_53519del p.Lys17840del inframe_deletion 278/3635 NM_001267550.2 ENSP00000467141 P1
TTN-AS1ENST00000659121.1 linkuse as main transcriptn.502+9402_502+9404del intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.00000404
AC:
1
AN:
247548
Hom.:
0
AF XY:
0.00000745
AC XY:
1
AN XY:
134226
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000291
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
Data not reliable, filtered out with message: AS_VQSR
AF:
6.85e-7
AC:
1
AN:
1460154
Hom.:
0
AF XY:
0.00000138
AC XY:
1
AN XY:
726254
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:
0.00
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not specified Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineJul 17, 2014The Lys15272del variant in TTN has not been reported in individuals with cardiom yopathy or in large population studies. This variant is a deletion of the lysine (Lys) residue at position 15272 and is not predicted to alter the protein readi ng-frame. It is currently unclear how this deletion would impact the protein. Ad ditional information is needed to fully assess the clinical significance of the Lys15272del variant. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.050
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.

Other links and lift over

dbSNP: rs727504701; hg19: chr2-179471809; API