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rs876658047

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 1P and 1B. PP2BP4

The NM_001267550.2(TTN):c.2206G>A(p.Gly736Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000013 in 1,613,964 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/18 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 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

1
3
12

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:1

Conservation

PhyloP100: 1.86
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

PP2
Missense variant where missense usually causes diseases, TTN
BP4
Computational evidence support a benign effect (MetaRNN=0.26788798).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
TTNNM_001267550.2 linkuse as main transcriptc.2206G>A p.Gly736Arg missense_variant 14/363 ENST00000589042.5
TTNNM_133379.5 linkuse as main transcriptc.2206G>A p.Gly736Arg missense_variant 14/46 ENST00000360870.10

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
TTNENST00000589042.5 linkuse as main transcriptc.2206G>A p.Gly736Arg missense_variant 14/3635 NM_001267550.2 P1
TTNENST00000360870.10 linkuse as main transcriptc.2206G>A p.Gly736Arg missense_variant 14/465 NM_133379.5 Q8WZ42-6

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152146
Hom.:
0
Cov.:
32
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:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00000797
AC:
2
AN:
250958
Hom.:
0
AF XY:
0.00000737
AC XY:
1
AN XY:
135600
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS 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:
0.0000137
AC:
20
AN:
1461818
Hom.:
0
Cov.:
35
AF XY:
0.00000825
AC XY:
6
AN XY:
727212
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.0000447
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000135
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152146
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74316
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.0000655
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000113

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:3Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:1
Likely benign, criteria provided, single submitterclinical testingGeneDxNov 23, 2018- -
Uncertain significance, criteria provided, single submitterclinical testingMayo Clinic Laboratories, Mayo ClinicJul 26, 2021- -
not specified Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineFeb 05, 2015Variant classified as Uncertain Significance - Favor Benign. The p.Gly736Arg var iant in TTN has not been previously reported in individuals with cardiomyopathy or in large population studies. Glycine (Gly) at position 736 is not conserved i n mammals or in evolutionarily distant species with 1 primate (gorilla) having a n arginine (Arg) at this position, suggesting that this change may be tolerated. Additional computational prediction tools suggest that this variant may not imp act the protein, though this information is not predictive enough to rule out pa thogenicity. In summary, while the clinical significance of the p.Gly736Arg vari ant is uncertain, the presence of the variant amino acid in another primate sugg ests that it is more likely to be benign. -
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingInvitaeDec 04, 2017- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.29
BayesDel_addAF
Benign
-0.15
T
BayesDel_noAF
Benign
-0.27
Cadd
Benign
21
Dann
Benign
0.97
Eigen
Benign
-0.25
Eigen_PC
Benign
-0.084
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Benign
0.74
T;T;T;.;T;T;T;T
M_CAP
Benign
0.041
D
MetaRNN
Benign
0.27
T;T;T;T;T;T;T;T
MetaSVM
Benign
-0.90
T
MutationTaster
Benign
0.87
D;N;N;N;N;N;N
PrimateAI
Uncertain
0.49
T
PROVEAN
Uncertain
-4.3
D;D;.;.;D;D;.;D
REVEL
Benign
0.17
Sift
Pathogenic
0.0
D;D;.;.;D;D;.;D
Polyphen
0.036, 0.43
.;.;.;B;.;.;B;B
Vest4
0.33
MutPred
0.27
Gain of MoRF binding (P = 0.0073);.;Gain of MoRF binding (P = 0.0073);Gain of MoRF binding (P = 0.0073);.;.;Gain of MoRF binding (P = 0.0073);Gain of MoRF binding (P = 0.0073);
MVP
0.50
MPC
0.10
ClinPred
0.42
T
GERP RS
5.3

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs876658047; hg19: chr2-179650739; COSMIC: COSV60107741; COSMIC: COSV60107741; API