rs878854378
Positions:
Variant summary
Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PM4_SupportingPP5
The NM_001267550.2(TTN):c.102956_102958del(p.Thr34319del) variant causes a inframe deletion change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Genomes: not found (cov: 32)
Consequence
TTN
NM_001267550.2 inframe_deletion
NM_001267550.2 inframe_deletion
Scores
Not classified
Clinical Significance
Conservation
PhyloP100: 5.34
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]
Genome browser will be placed here
ACMG classification
Classification made for transcript
Verdict is Uncertain_significance. Variant got 4 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.
PP5
Variant 2-178533656-ATTG-A is Pathogenic according to our data. Variant chr2-178533656-ATTG-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 242429.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}. Variant chr2-178533656-ATTG-A is described in Lovd as [Likely_pathogenic].
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
|---|---|---|---|---|---|---|---|
| TTN | NM_001267550.2 | c.102956_102958del | p.Thr34319del | inframe_deletion | 358/363 | ENST00000589042.5 | |
| TTN-AS1 | NR_038272.1 | n.220-2073_220-2071del | intron_variant, non_coding_transcript_variant |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| TTN | ENST00000589042.5 | c.102956_102958del | p.Thr34319del | inframe_deletion | 358/363 | 5 | NM_001267550.2 | P1 | |
| TTN-AS1 | ENST00000659121.1 | n.416+10023_416+10025del | intron_variant, non_coding_transcript_variant |
Frequencies
GnomAD3 genomes
GnomAD3 genomes
Cov.:
32
We have no GnomAD4 exomes data on this position. Probably position not covered by the project.
GnomAD4 genome
GnomAD4 genome
Cov.:
32
ClinVar
Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link
Submissions by phenotype
Autosomal recessive limb-girdle muscular dystrophy type 2J Pathogenic:1
| Likely pathogenic, criteria provided, single submitter | clinical testing | Undiagnosed Diseases Network, NIH | Dec 05, 2018 | A heterozygous c.55018C>T (p.R18340X) pathogenic variant in the TTN gene was detected in this individual. A heterozygous c.95252_95254delCAA (p.T31751del) likely pathogenic variant in the TTN gene was also detected. A heterozygous c.74698A>C (p.K24900Q) variant was also detected and found to be likely benign. The c.55018C>T (p.R18340X) variant is in trans configuration with the c.95252_95254delCAA (p.T31751del) and c.74698A>C (p.K24900Q) variants. - |
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 | Dec 06, 2023 | This variant, c.102956_102958del, results in the deletion of 1 amino acid(s) of the TTN protein (p.Thr34319del), but otherwise preserves the integrity of the reading frame. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individual(s) with limb-girdle muscular dystrophy (PMID: 27854218). ClinVar contains an entry for this variant (Variation ID: 242429). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. This variant is located in the M band of TTN (PMID: 25589632). Non-truncating variants in this region may be relevant for neuromuscular disorders, but have not been definitively shown to cause cardiomyopathy (PMID: 23975875). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. - |
Computational scores
Source:
Name
Calibrated prediction
Score
Prediction
Splicing
Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
Details are displayed if max score is > 0.2
Find out detailed SpliceAI scores and Pangolin per-transcript scores at