rs200240728

Variant summary

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

The NM_001267550.2(TTN):​c.81869G>C​(p.Gly27290Ala) variant causes a missense change. The variant allele was found at a frequency of 0.0000769 in 1,613,270 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 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. G27290R) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00011 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000074 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

5
7
5

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 5.00

Publications

3 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=0.30380422).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.81869G>C p.Gly27290Ala missense_variant Exon 326 of 363 ENST00000589042.5 NP_001254479.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.81869G>C p.Gly27290Ala missense_variant Exon 326 of 363 5 NM_001267550.2 ENSP00000467141.1

Frequencies

GnomAD3 genomes
AF:
0.000105
AC:
16
AN:
152128
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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:
0.000206
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000968
AC:
24
AN:
248002
AF XY:
0.000134
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000869
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000125
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000739
AC:
108
AN:
1461024
Hom.:
0
Cov.:
37
AF XY:
0.0000826
AC XY:
60
AN XY:
726824
show subpopulations
African (AFR)
AF:
0.0000896
AC:
3
AN:
33468
American (AMR)
AF:
0.000112
AC:
5
AN:
44716
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39682
South Asian (SAS)
AF:
0.000301
AC:
26
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52868
Middle Eastern (MID)
AF:
0.000867
AC:
5
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000594
AC:
66
AN:
1111772
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60366
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.476
Heterozygous variant carriers
0
8
16
23
31
39
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:
152246
Hom.:
0
Cov.:
33
AF XY:
0.000121
AC XY:
9
AN XY:
74444
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41562
American (AMR)
AF:
0.0000654
AC:
1
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5162
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000206
AC:
14
AN:
68008
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.513
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.000119
Hom.:
0
Bravo
AF:
0.0000869
ExAC
AF:
0.000132
AC:
16
EpiCase
AF:
0.000327
EpiControl
AF:
0.000356

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:3
Jan 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

TTN: PM2 -

Sep 27, 2022
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dec 07, 2017
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1
Mar 21, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: TTN c.74165G>C (p.Gly24722Ala) results in a non-conservative amino acid change located in the A-band region of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 9.7e-05 in 248002 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in TTN causing Dilated Cardiomyopathy (9.7e-05 vs 0.00039), allowing no conclusion about variant significance. To our knowledge, no occurrence of c.74165G>C in individuals affected with Dilated Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 404659). Based on the evidence outlined above, the variant was classified as uncertain significance. -

TTN-related disorder Uncertain:1
Dec 16, 2023
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

The TTN c.81869G>C variant is predicted to result in the amino acid substitution p.Gly27290Ala. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.023% of alleles in individuals of South Asian descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
May 22, 2016
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.50
BayesDel_addAF
Benign
-0.087
T
BayesDel_noAF
Uncertain
-0.070
CADD
Benign
20
DANN
Benign
0.89
Eigen
Pathogenic
0.94
Eigen_PC
Pathogenic
0.89
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.92
D;D;D;.;D;D;D
M_CAP
Benign
0.028
D
MetaRNN
Benign
0.30
T;T;T;T;T;T;T
MetaSVM
Uncertain
0.66
D
MutationAssessor
Pathogenic
3.9
.;.;.;H;.;.;H
PhyloP100
5.0
PrimateAI
Uncertain
0.62
T
PROVEAN
Uncertain
-4.3
D;D;.;.;D;D;.
REVEL
Uncertain
0.60
Sift
Pathogenic
0.0
D;D;.;.;D;D;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.48
MVP
0.64
MPC
0.46
ClinPred
0.44
T
GERP RS
6.1
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Mutation Taster
=48/52
disease causing

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: rs200240728; hg19: chr2-179428990; API