rs199889888
Variant summary
Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.
The NM_001267550.2(TTN):c.3913G>T(p.Gly1305Trp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000403 in 1,613,724 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G1305R) has been classified as Likely benign.
Frequency
Consequence
NM_001267550.2 missense
Scores
Clinical Significance
Conservation
Publications
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ACMG classification
Our verdict: Uncertain_significance. The variant received 0 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| TTN | NM_001267550.2 | c.3913G>T | p.Gly1305Trp | missense_variant | Exon 23 of 363 | ENST00000589042.5 | NP_001254479.2 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| TTN | ENST00000589042.5 | c.3913G>T | p.Gly1305Trp | missense_variant | Exon 23 of 363 | 5 | NM_001267550.2 | ENSP00000467141.1 |
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152194Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000640 AC: 16AN: 250082 AF XY: 0.0000961 show subpopulations
GnomAD4 exome AF: 0.0000424 AC: 62AN: 1461530Hom.: 0 Cov.: 53 AF XY: 0.0000454 AC XY: 33AN XY: 727080 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152194Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2AN XY: 74336 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:4Benign:1
PP3
not specified Uncertain:2
The Gly1305Trp variant in TTN has not been previously reported in individuals wi th cardiomyopathy or in large population studies. Computational analyses (bioche mical amino acid properties, conservation, AlignGVGD, PolyPhen2, and SIFT) sugge st that the Gly1305Trp variant may impact the protein, though this information i s not predictive enough to determine pathogenicity. Additional information is ne eded to fully assess the clinical significance of the Gly1305Trp variant
Variant summary: TTN c.3913G>T (p.Gly1305Trp) results in a non-conservative amino acid change located in the near Z-disk region of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 6.4e-05 in 250082 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in TTN causing Dilated Cardiomyopathy (6.4e-05 vs 0.00039), allowing no conclusion about variant significance. c.3913G>T has been reported in the literature in at least one individual affected with familial atrial fibrillation (Maltese_2019). This report does not provide unequivocal conclusions about association of the variant with Dilated Cardiomyopathy. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 31539150). Six submitters have cited clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as VUS (n=5) or likely benign (n=1). Based on the evidence outlined above, the variant was classified as uncertain significance.
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Cardiomyopathy Uncertain:1
Cardiovascular phenotype Uncertain:1
The p.G1259W variant (also known as c.3775G>T), located in coding exon 21 of the TTN gene, results from a G to T substitution at nucleotide position 3775. The glycine at codon 1259 is replaced by tryptophan, an amino acid with highly dissimilar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at