rs763483590

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2BP4

The NM_001267550.2(TTN):​c.50189C>T​(p.Ala16730Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,468 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

1
5
11

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 8.09

Publications

2 publications found
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 was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.3057288).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.50189C>T p.Ala16730Val missense_variant Exon 266 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.50189C>T p.Ala16730Val missense_variant Exon 266 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.00000404
AC:
1
AN:
247706
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000565
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
6.85e-7
AC:
1
AN:
1460468
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
726552
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33404
American (AMR)
AF:
0.00
AC:
0
AN:
44652
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26106
East Asian (EAS)
AF:
0.0000253
AC:
1
AN:
39458
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86224
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53342
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5752
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111244
Other (OTH)
AF:
0.00
AC:
0
AN:
60286
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
33
ExAC
AF:
0.00000828
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Apr 10, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Jun 09, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Uncertain:1
Aug 14, 2019
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.A7665V variant (also known as c.22994C>T), located in coding exon 93 of the TTN gene, results from a C to T substitution at nucleotide position 22994. The alanine at codon 7665 is replaced by valine, an amino acid with similar properties. This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.30
BayesDel_addAF
Benign
-0.16
T
BayesDel_noAF
Benign
-0.30
CADD
Benign
23
DANN
Benign
0.96
Eigen
Uncertain
0.56
Eigen_PC
Uncertain
0.65
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.95
D;D;D;.;D;D;D
M_CAP
Benign
0.016
T
MetaRNN
Benign
0.31
T;T;T;T;T;T;T
MetaSVM
Benign
-0.85
T
MutationAssessor
Benign
1.3
.;.;.;L;.;.;L
PhyloP100
8.1
PrimateAI
Uncertain
0.77
T
PROVEAN
Uncertain
-2.7
D;D;.;.;D;D;.
REVEL
Benign
0.21
Sift
Benign
0.057
T;D;.;.;T;T;.
Polyphen
0.95
.;.;.;P;.;.;P
Vest4
0.45
MutPred
0.48
.;.;.;Gain of catalytic residue at A15089 (P = 0.0592);.;.;Gain of catalytic residue at A15089 (P = 0.0592);
MVP
0.48
MPC
0.23
ClinPred
0.48
T
GERP RS
5.7
Mutation Taster
=92/8
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs763483590; hg19: chr2-179477063; API