rs371552518
Variant summary
Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.
The NM_001267550.2(TTN):āc.14309A>Gā(p.Tyr4770Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000105 in 1,613,764 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
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.14309A>G | p.Tyr4770Cys | missense_variant | Exon 49 of 363 | ENST00000589042.5 | NP_001254479.2 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| TTN | ENST00000589042.5 | c.14309A>G | p.Tyr4770Cys | missense_variant | Exon 49 of 363 | 5 | NM_001267550.2 | ENSP00000467141.1 |
Frequencies
GnomAD3 genomes AF: 0.0000920 AC: 14AN: 152242Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.000101 AC: 25AN: 248660 AF XY: 0.000104 show subpopulations
GnomAD4 exome AF: 0.000107 AC: 156AN: 1461522Hom.: 0 Cov.: 30 AF XY: 0.000102 AC XY: 74AN XY: 727042 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000920 AC: 14AN: 152242Hom.: 0 Cov.: 32 AF XY: 0.0000941 AC XY: 7AN XY: 74376 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:4
The TTN c.14309A>G; p.Tyr4770Cys variant (rs371552518; ClinVar Variation ID: 166226) is rare in the general population (<0.2% allele frequency in the Genome Aggregation Database) and has not been reported in the medical literature in association with dilated cardiomyopathy (DCM) or other TTN-related disease. The clinical relevance of rare missense variants in this gene, which are identified on average once per individual sequenced in affected populations (Herman 2012), is not well understood. Yet, evidence suggests that the vast majority of such missense variants do not contribute to the clinical outcome of DCM (Begay 2015). Thus, the clinical significance of the p.Tyr4770Cys variant cannot be determined with certainty. References: Begay RL et al. Role of Titin Missense Variants in Dilated Cardiomyopathy. J Am Heart Assoc. 2015 Nov 13;4(11). Herman DS et al. Truncations of titin causing dilated cardiomyopathy. N Engl J Med. 2012 Feb 16;366(7):619-28. Linke WA and Hamdani N. Gigantic business: titin properties and function through thick and thin. Circ Res 2014; 114(6): 1052-1068. -
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not specified Uncertain:3Benign:1
Missense variants in the TTN gene are considered 'unclassified' if they are not previously reported in the literature and do not have >1% frequency in the population to be considered a polymorphism. Research indicates that truncating mutations in the TTN gene are expected to account for approximately 25% of familial and 18% of sporadic idiopathic DCM; however, truncating variants in the TTN gene have been reported in approximately 3% of reported control alleles. There has been little investigation into non-truncating variants. (Herman D et al. Truncations of titin causing dilated cardiomyopathy. N Eng J Med 366:619-628, 2012) The variant is found in DCM,CARDIOMYOPATHY panel(s). -
Variant summary: TTN c.10577A>G (p.Tyr3526Cys) results in a non-conservative amino acid change located in the I-Band 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 0.0001 in 248660 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in TTN causing Dilated Cardiomyopathy (0.0001 vs 0.00039), allowing no conclusion about variant significance. c.10577A>G has been reported in the literature in individuals affected with Dilated Cardiomyopathy or suspected neuromuscular disorder (Wasielewski_2014, Westra_2019, Verdonschot_2020). These report(s) do 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 publications have been ascertained in the context of this evaluation (PMID: 37198425, 32880476, 25332820, 31127727). ClinVar contains an entry for this variant (Variation ID: 166226). Based on the evidence outlined above, the variant was classified as uncertain significance. -
The p.Tyr3526Cys variant in TTN has been identified by our laboratory in 1 Cauca sian adult with DCM. It has also been identified in 13/66560 European chromosome s by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; dbS NP rs371552518). Computational prediction tools and conservation analysis do no t provide strong support for or against an impact to the protein. In summary, th e clinical significance of the p.Tyr3526Cys variant is uncertain. -
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Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
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Dilated cardiomyopathy 1G Uncertain:1
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Cardiomyopathy Uncertain:1
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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
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Cardiovascular phenotype Uncertain:1
The p.Y4407C variant (also known as c.13220A>G), located in coding exon 45 of the TTN gene, results from an A to G substitution at nucleotide position 13220. The tyrosine at codon 4407 is replaced by cysteine, an amino acid with highly dissimilar properties. This variant, reported as p.Y4453C ( c.13358A>G), was detected in conjunction with other cardiac related variants in a proband with anthracycline-associated cardiomyopathy (Wasielewski M. Open Heart. 2014 Jul;1(1):e000116). 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