2-178599153-G-T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6

The NM_001267550.2(TTN):​c.56640C>A​(p.Asn18880Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000173 in 1,505,286 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 Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. N18880N) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00011 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000074 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

3
4
10

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:1

Conservation

PhyloP100: 1.72

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 -3 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.21229121).
BP6
Variant 2-178599153-G-T is Benign according to our data. Variant chr2-178599153-G-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 238802.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.56640C>A p.Asn18880Lys missense_variant Exon 290 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.56640C>A p.Asn18880Lys missense_variant Exon 290 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.000105
AC:
16
AN:
151980
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000387
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000413
AC:
7
AN:
169664
AF XY:
0.0000556
show subpopulations
Gnomad AFR exome
AF:
0.000496
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:
0.00000739
AC:
10
AN:
1353306
Hom.:
0
Cov.:
32
AF XY:
0.00000907
AC XY:
6
AN XY:
661824
show subpopulations
African (AFR)
AF:
0.000235
AC:
7
AN:
29728
American (AMR)
AF:
0.00
AC:
0
AN:
27212
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
19800
East Asian (EAS)
AF:
0.00
AC:
0
AN:
38102
South Asian (SAS)
AF:
0.0000154
AC:
1
AN:
64936
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
49722
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5286
European-Non Finnish (NFE)
AF:
9.41e-7
AC:
1
AN:
1062858
Other (OTH)
AF:
0.0000180
AC:
1
AN:
55662
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
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:
0.000105
AC:
16
AN:
151980
Hom.:
0
Cov.:
32
AF XY:
0.000135
AC XY:
10
AN XY:
74218
show subpopulations
African (AFR)
AF:
0.000387
AC:
16
AN:
41394
American (AMR)
AF:
0.00
AC:
0
AN:
15254
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5132
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67974
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.509
Heterozygous variant carriers
0
1
3
4
6
7
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.0000318
Hom.:
0
Bravo
AF:
0.000102
ESP6500AA
AF:
0.000806
AC:
3
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000419
AC:
5

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Feb 06, 2016
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Feb 27, 2019
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Benign:1
Apr 17, 2020
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.87
BayesDel_addAF
Benign
-0.40
T
BayesDel_noAF
Benign
-0.44
CADD
Benign
15
DANN
Benign
0.94
Eigen
Benign
0.14
Eigen_PC
Benign
0.061
FATHMM_MKL
Uncertain
0.91
D
LIST_S2
Uncertain
0.91
D;D;D;.;D;D;D
M_CAP
Benign
0.025
T
MetaRNN
Benign
0.21
T;T;T;T;T;T;T
MetaSVM
Benign
-0.73
T
MutationAssessor
Uncertain
2.9
.;.;.;M;.;.;M
PhyloP100
1.7
PrimateAI
Pathogenic
0.80
T
PROVEAN
Pathogenic
-4.4
D;D;.;.;D;D;.
REVEL
Benign
0.25
Sift
Uncertain
0.015
D;D;.;.;D;D;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.58
MutPred
0.43
.;.;.;Gain of ubiquitination at N17239 (P = 0.017);.;.;Gain of ubiquitination at N17239 (P = 0.017);
MVP
0.20
MPC
0.49
ClinPred
0.42
T
GERP RS
0.51
Mutation Taster
=64/36
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: rs200544272; hg19: chr2-179463880; API