2-178728127-C-T

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BP4

The NM_001267550.2(TTN):​c.19697G>A​(p.Gly6566Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000504 in 1,587,052 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G6566A) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000049 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

1
9
6

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 1.69

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: Likely_benign. The variant received -1 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.42353818).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.19697G>A p.Gly6566Asp missense_variant Exon 67 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.19697G>A p.Gly6566Asp missense_variant Exon 67 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
152074
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00
AC:
0
AN:
228870
AF XY:
0.00
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000488
AC:
7
AN:
1434978
Hom.:
0
Cov.:
32
AF XY:
0.00000281
AC XY:
2
AN XY:
710608
show subpopulations
African (AFR)
AF:
0.0000306
AC:
1
AN:
32694
American (AMR)
AF:
0.00
AC:
0
AN:
42200
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
24494
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39316
South Asian (SAS)
AF:
0.0000247
AC:
2
AN:
80982
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52304
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5608
European-Non Finnish (NFE)
AF:
0.00000364
AC:
4
AN:
1098172
Other (OTH)
AF:
0.00
AC:
0
AN:
59208
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.432
Heterozygous variant carriers
0
1
2
2
3
4
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
AF:
0.00000658
AC:
1
AN:
152074
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74264
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41432
American (AMR)
AF:
0.00
AC:
0
AN:
15254
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67994
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), 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
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.88
BayesDel_addAF
Uncertain
0.13
D
BayesDel_noAF
Uncertain
-0.050
CADD
Benign
20
DANN
Benign
0.73
Eigen
Uncertain
0.38
Eigen_PC
Uncertain
0.30
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Benign
0.76
T;T;.;T
M_CAP
Benign
0.083
D
MetaRNN
Benign
0.42
T;T;T;T
MetaSVM
Uncertain
-0.22
T
PhyloP100
1.7
PrimateAI
Uncertain
0.64
T
PROVEAN
Uncertain
-3.9
D;.;.;.
REVEL
Uncertain
0.52
Sift
Benign
0.088
T;.;.;.
Polyphen
0.99
.;.;D;D
Vest4
0.50
MutPred
0.51
.;.;Gain of loop (P = 0.1069);Gain of loop (P = 0.1069);
MVP
0.42
MPC
0.38
ClinPred
0.35
T
GERP RS
1.5
Mutation Taster
=66/34
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: rs1052515116; hg19: chr2-179592854; API