NM_001267550.2:c.69853G>A

Variant summary

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

The NM_001267550.2(TTN):​c.69853G>A​(p.Glu23285Lys) variant causes a missense change. The variant allele was found at a frequency of 0.0000642 in 1,604,368 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00019 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000051 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

1
2
14

Clinical Significance

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

Conservation

PhyloP100: 6.12

Publications

1 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=0.087809).
BP6
Variant 2-178576279-C-T is Benign according to our data. Variant chr2-178576279-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 178194.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.69853G>A p.Glu23285Lys 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.69853G>A p.Glu23285Lys missense_variant Exon 326 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.000197
AC:
30
AN:
152018
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000628
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000656
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000546
AC:
13
AN:
238236
AF XY:
0.0000387
show subpopulations
Gnomad AFR exome
AF:
0.000396
Gnomad AMR exome
AF:
0.0000904
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000278
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000510
AC:
74
AN:
1452232
Hom.:
0
Cov.:
36
AF XY:
0.0000485
AC XY:
35
AN XY:
721826
show subpopulations
African (AFR)
AF:
0.000334
AC:
11
AN:
32902
American (AMR)
AF:
0.0000923
AC:
4
AN:
43344
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25574
East Asian (EAS)
AF:
0.0000253
AC:
1
AN:
39500
South Asian (SAS)
AF:
0.0000118
AC:
1
AN:
84416
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52820
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5706
European-Non Finnish (NFE)
AF:
0.0000505
AC:
56
AN:
1108056
Other (OTH)
AF:
0.0000167
AC:
1
AN:
59914
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.469
Heterozygous variant carriers
0
5
11
16
22
27
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.000191
AC:
29
AN:
152136
Hom.:
0
Cov.:
32
AF XY:
0.000134
AC XY:
10
AN XY:
74362
show subpopulations
African (AFR)
AF:
0.000602
AC:
25
AN:
41534
American (AMR)
AF:
0.0000655
AC:
1
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5140
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
67972
Other (OTH)
AF:
0.00
AC:
0
AN:
2108
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.503
Heterozygous variant carriers
0
2
4
5
7
9
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:
0.000117
Hom.:
0
Bravo
AF:
0.000204
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000259
AC:
1
ESP6500AA
AF:
0.000522
AC:
2
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000911
AC:
11

ClinVar

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

Submissions by phenotype

not specified Uncertain:1
Jun 12, 2013
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The Glu20717Lys variant in TTN has not been reported in individuals with cardiom yopathy, but has been identified in 2/3830 African American chromosomes by the N HLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS/). Computational analyses (biochemical amino acid properties, conservation, AlignGVGD, and PolyP hen2) suggest that this variant may not impact the protein, though this informat ion is not predictive enough to rule out pathogenicity. Additional information i s needed to fully assess the clinical significance of the Glu20717Lys variant. -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Dec 11, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Benign:1
Oct 01, 2020
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Benign:1
Aug 19, 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
Benign
0.088
BayesDel_addAF
Benign
-0.29
T
BayesDel_noAF
Benign
-0.34
CADD
Benign
21
DANN
Benign
0.77
Eigen
Benign
0.16
Eigen_PC
Benign
0.19
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.88
D;D;D;.;D;D;D
M_CAP
Benign
0.034
D
MetaRNN
Benign
0.088
T;T;T;T;T;T;T
MetaSVM
Benign
-0.75
T
MutationAssessor
Benign
1.3
.;.;.;L;.;.;L
PhyloP100
6.1
PrimateAI
Benign
0.41
T
PROVEAN
Uncertain
-2.6
D;D;.;.;D;D;.
REVEL
Benign
0.23
Sift
Benign
0.073
T;T;.;.;T;T;.
Polyphen
0.61
.;.;.;P;.;.;P
Vest4
0.38
MVP
0.24
MPC
0.14
ClinPred
0.043
T
GERP RS
5.9
Mutation Taster
=65/35
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: rs376870149; hg19: chr2-179441006; COSMIC: COSV60077361; COSMIC: COSV60077361; API