NM_001267550.2:c.83785G>A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.

The NM_001267550.2(TTN):​c.83785G>A​(p.Gly27929Arg) variant causes a missense change. The variant allele was found at a frequency of 0.0000158 in 1,458,800 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G27929K) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

6
8
3

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 4.90

Publications

0 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 0 ACMG points.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.83785G>A p.Gly27929Arg missense_variant Exon 326 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.83785G>A p.Gly27929Arg missense_variant Exon 326 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.0000163
AC:
4
AN:
245352
AF XY:
0.0000225
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000560
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000269
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000158
AC:
23
AN:
1458800
Hom.:
0
Cov.:
32
AF XY:
0.0000221
AC XY:
16
AN XY:
725566
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33296
American (AMR)
AF:
0.00
AC:
0
AN:
44412
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25932
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39654
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85622
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53118
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5754
European-Non Finnish (NFE)
AF:
0.0000198
AC:
22
AN:
1110780
Other (OTH)
AF:
0.00
AC:
0
AN:
60232
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.462
Heterozygous variant carriers
0
2
4
6
8
10
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
33

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:1
Jun 24, 2013
Biesecker Lab/Clinical Genomics Section, National Institutes of Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:research

- -

Cardiovascular phenotype Uncertain:1
Mar 02, 2017
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.G18864R variant (also known as c.56590G>A), located in coding exon 153 of the TTN gene, results from a G to A substitution at nucleotide position 56590. The glycine at codon 18864 is replaced by arginine, an amino acid with dissimilar properties. This alteration has been reported as a secondary cardiac variant in an exome cohort (Ng D et al. Circ Cardiovasc Genet, 2013 Aug;6:337-46). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. 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
Uncertain
0.55
BayesDel_addAF
Uncertain
0.042
T
BayesDel_noAF
Uncertain
-0.010
CADD
Benign
21
DANN
Benign
0.94
Eigen
Pathogenic
0.94
Eigen_PC
Pathogenic
0.90
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Pathogenic
1.0
D;D;D;.;D;D;D
M_CAP
Benign
0.050
D
MetaRNN
Uncertain
0.59
D;D;D;D;D;D;D
MetaSVM
Uncertain
0.21
D
MutationAssessor
Pathogenic
3.3
.;.;.;M;.;.;M
PhyloP100
4.9
PrimateAI
Uncertain
0.58
T
PROVEAN
Pathogenic
-5.0
D;D;.;.;D;D;.
REVEL
Uncertain
0.47
Sift
Uncertain
0.0030
D;D;.;.;D;D;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.49
MutPred
0.70
.;.;.;Gain of phosphorylation at T26286 (P = 0.1362);.;.;Gain of phosphorylation at T26286 (P = 0.1362);
MVP
0.59
MPC
0.46
ClinPred
0.67
D
GERP RS
5.9
Mutation Taster
=58/42
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: rs786205297; hg19: chr2-179427074; API