rs876657672
Positions:
Variant summary
Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1_ModeratePM2PP3_StrongPP5_Moderate
The NM_001267550.2(TTN):c.99866-1G>A variant causes a splice acceptor change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).
Frequency
Genomes: not found (cov: 33)
Consequence
TTN
NM_001267550.2 splice_acceptor
NM_001267550.2 splice_acceptor
Scores
5
1
1
Splicing: ADA: 1.000
2
Clinical Significance
Conservation
PhyloP100: 7.91
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]
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ACMG classification
Classification made for transcript
Verdict is Pathogenic. Variant got 10 ACMG points.
PVS1
Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.0028247018 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
PP5
Variant 2-178537244-C-T is Pathogenic according to our data. Variant chr2-178537244-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 228309.Status of the report is criteria_provided_single_submitter, 1 stars.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
---|---|---|---|---|---|---|---|
TTN | NM_001267550.2 | c.99866-1G>A | splice_acceptor_variant | ENST00000589042.5 | |||
TTN-AS1 | NR_038272.1 | n.317-117C>T | intron_variant, non_coding_transcript_variant |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|
TTN | ENST00000589042.5 | c.99866-1G>A | splice_acceptor_variant | 5 | NM_001267550.2 | P1 | |||
TTN-AS1 | ENST00000659121.1 | n.416+13608C>T | intron_variant, non_coding_transcript_variant |
Frequencies
GnomAD3 genomes Cov.: 33
GnomAD3 genomes
Cov.:
33
GnomAD4 exome Cov.: 32
GnomAD4 exome
Cov.:
32
GnomAD4 genome Cov.: 33
GnomAD4 genome
Cov.:
33
ClinVar
Significance: Likely pathogenic
Submissions summary: Pathogenic:1
Revision: criteria provided, single submitter
LINK: link
Submissions by phenotype
Primary dilated cardiomyopathy Pathogenic:1
Likely pathogenic, criteria provided, single submitter | clinical testing | Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine | Aug 13, 2015 | The c.92162-1G>A variant in TTN has not been previously reported in individuals with cardiomyopathy or in large population studies. This variant occurs in the i nvariant region (+/- 1,2) of the splice consensus sequence and is predicted to c ause altered splicing leading to an abnormal or absent protein. Splice and other truncating variants in TTN are strongly associated with DCM if they are located in the exons encoding for the A-band region (exons 201-306) of the protein (Her man 2012, Pugh 2014), where this variant is located. In summary, although additi onal studies are required to fully establish its clinical significance, the c.92 162-1G>A variant is likely pathogenic. - |
Computational scores
Source:
Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
D
BayesDel_noAF
Pathogenic
CADD
Pathogenic
DANN
Uncertain
Eigen
Pathogenic
Eigen_PC
Pathogenic
FATHMM_MKL
Pathogenic
D
MutationTaster
Benign
D;D;D;D;D;D
GERP RS
Splicing
Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
dbscSNV1_RF
Pathogenic
SpliceAI score (max)
Details are displayed if max score is > 0.2
DS_AG_spliceai
Position offset: -10
DS_AL_spliceai
Position offset: -1
Find out detailed SpliceAI scores and Pangolin per-transcript scores at