rs201364164

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PP3_ModerateBP6

The NM_001267550.2(TTN):​c.97442G>A​(p.Gly32481Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000707 in 1,612,626 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G32481R) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000074 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

8
5
4

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:2

Conservation

PhyloP100: 7.91

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: Uncertain_significance. The variant received 1 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.884
BP6
Variant 2-178542314-C-T is Benign according to our data. Variant chr2-178542314-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 203028.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.97442G>A p.Gly32481Glu missense_variant Exon 349 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.97442G>A p.Gly32481Glu missense_variant Exon 349 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152108
Hom.:
0
Cov.:
32
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:
0.000414
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000588
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000893
AC:
22
AN:
246442
AF XY:
0.0000972
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000583
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000359
Gnomad OTH exome
AF:
0.000668
GnomAD4 exome
AF:
0.0000740
AC:
108
AN:
1460400
Hom.:
1
Cov.:
32
AF XY:
0.0000798
AC XY:
58
AN XY:
726398
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33442
American (AMR)
AF:
0.0000673
AC:
3
AN:
44606
Ashkenazi Jewish (ASJ)
AF:
0.0000766
AC:
2
AN:
26098
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39504
South Asian (SAS)
AF:
0.000407
AC:
35
AN:
86040
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53314
Middle Eastern (MID)
AF:
0.00226
AC:
13
AN:
5762
European-Non Finnish (NFE)
AF:
0.0000360
AC:
40
AN:
1111304
Other (OTH)
AF:
0.000232
AC:
14
AN:
60330
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.476
Heterozygous variant carriers
0
6
13
19
26
32
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
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:
0.0000394
AC:
6
AN:
152226
Hom.:
0
Cov.:
32
AF XY:
0.0000672
AC XY:
5
AN XY:
74414
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41552
American (AMR)
AF:
0.00
AC:
0
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5162
South Asian (SAS)
AF:
0.000415
AC:
2
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10608
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000588
AC:
4
AN:
68002
Other (OTH)
AF:
0.00
AC:
0
AN:
2110
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.567
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.000113
Hom.:
0
Bravo
AF:
0.0000340
ExAC
AF:
0.0000910
AC:
11

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:4Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2Benign:1
Jun 29, 2018
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Sep 12, 2019
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Apr 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

TTN: PM2, PP3 -

not specified Uncertain:1
Feb 06, 2025
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.89738G>A (p.Gly29913Glu) results in a non-conservative amino acid change located in the Fibronectin type-III domain profile (IPR003961) of the encoded protein sequence. Four of four in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8.9e-05 in 246442 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in TTN causing Autosomal Recessive Titinopathy (8.9e-05 vs 0.00039), allowing no conclusion about variant significance. To our knowledge, no occurrence of c.89738G>A in individuals affected with Autosomal Recessive Titinopathy and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 203028). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Dec 28, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiomyopathy Benign:1
Aug 30, 2021
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.99
BayesDel_addAF
Benign
-0.042
T
BayesDel_noAF
Uncertain
0.010
CADD
Benign
22
DANN
Benign
0.96
Eigen
Pathogenic
1.2
Eigen_PC
Pathogenic
1.1
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.90
D;D;D;.;D;D;D
M_CAP
Benign
0.038
D
MetaRNN
Pathogenic
0.88
D;D;D;D;D;D;D
MetaSVM
Uncertain
0.72
D
MutationAssessor
Pathogenic
3.9
.;.;.;H;.;.;H
PhyloP100
7.9
PrimateAI
Pathogenic
0.83
D
PROVEAN
Pathogenic
-5.9
D;D;.;.;D;D;.
REVEL
Uncertain
0.59
Sift
Uncertain
0.0040
D;D;.;.;D;D;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.68
MutPred
0.93
.;.;.;Gain of phosphorylation at Y30844 (P = 0.1298);.;.;Gain of phosphorylation at Y30844 (P = 0.1298);
MVP
0.76
MPC
0.53
ClinPred
0.51
D
GERP RS
6.2
Mutation Taster
=41/59
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: rs201364164; hg19: chr2-179407041; COSMIC: COSV59952029; COSMIC: COSV59952029; API