chr2-178584372-C-T

Variant summary

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

The NM_001267550.2(TTN):​c.65179G>A​(p.Gly21727Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000149 in 1,613,104 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 (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

4
7
6

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 7.86
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]
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 made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

PP2
Missense variant in gene, where missense usually causes diseases (based on misZ statistic), TTN. . Gene score misZ -1.1021 (greater than the threshold 3.09). Trascript score misZ 6.9794 (greater than threshold 3.09). GenCC has associacion of gene with dilated cardiomyopathy, tibial muscular dystrophy, early-onset myopathy with fatal cardiomyopathy, autosomal recessive centronuclear myopathy, hypertrophic cardiomyopathy, hypertrophic cardiomyopathy 9, TTN-related myopathy, dilated cardiomyopathy 1G, arrhythmogenic right ventricular cardiomyopathy, myopathy, myofibrillar, 9, with early respiratory failure, familial isolated dilated cardiomyopathy, childhood-onset progressive contractures-limb-girdle weakness-muscle dystrophy syndrome, autosomal recessive limb-girdle muscular dystrophy type 2J.
BP4
Computational evidence support a benign effect (MetaRNN=0.32631132).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
TTNNM_001267550.2 linkuse as main transcriptc.65179G>A p.Gly21727Ser missense_variant 311/363 ENST00000589042.5 NP_001254479.2
TTN-AS1NR_038272.1 linkuse as main transcriptn.2768-201C>T intron_variant, non_coding_transcript_variant

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkuse as main transcriptc.65179G>A p.Gly21727Ser missense_variant 311/3635 NM_001267550.2 ENSP00000467141 P1
TTN-AS1ENST00000659121.1 linkuse as main transcriptn.417-13224C>T intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
152044
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:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000242
AC:
6
AN:
248018
Hom.:
0
AF XY:
0.0000223
AC XY:
3
AN XY:
134516
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000290
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.0000327
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000268
Gnomad OTH exome
AF:
0.000166
GnomAD4 exome
AF:
0.0000151
AC:
22
AN:
1461060
Hom.:
0
Cov.:
32
AF XY:
0.0000165
AC XY:
12
AN XY:
726826
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000162
Gnomad4 OTH exome
AF:
0.0000331
GnomAD4 genome
AF:
0.0000132
AC:
2
AN:
152044
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74252
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000294
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000833
Hom.:
0
Bravo
AF:
0.0000113
ExAC
AF:
0.0000248
AC:
3
EpiCase
AF:
0.0000546
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineMay 28, 2015The p.Gly19159Ser variant in TTN has not been previously reported in individuals with cardiomyopathy but has been indentified in 2/11482 Latino chromosomes by t he Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org). Computat ional prediction tools and conservation analysis suggest that the variant may im pact the protein, though this information is not predictive enough to determine pathogenicity. In summary, the clinical significance of the p.Gly19159Ser varian t is uncertain. -
TTN-related disorder Uncertain:1
Uncertain significance, no assertion criteria providedclinical testingPreventionGenetics, part of Exact SciencesAug 08, 2024The TTN c.65179G>A variant is predicted to result in the amino acid substitution p.Gly21727Ser. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.0033% 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
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpMar 30, 2017- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.49
BayesDel_addAF
Benign
-0.020
T
BayesDel_noAF
Benign
-0.17
CADD
Benign
21
DANN
Benign
0.92
Eigen
Pathogenic
0.90
Eigen_PC
Pathogenic
0.90
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.91
D;D;D;.;D;D;D
M_CAP
Benign
0.027
D
MetaRNN
Benign
0.33
T;T;T;T;T;T;T
MetaSVM
Uncertain
-0.21
T
MutationAssessor
Uncertain
2.2
.;.;.;M;.;.;M
MutationTaster
Benign
1.0
D;D;D;D;D;D
PrimateAI
Uncertain
0.75
T
PROVEAN
Pathogenic
-4.5
D;D;.;.;D;D;.
REVEL
Uncertain
0.50
Sift
Uncertain
0.0070
D;D;.;.;D;D;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.44
MutPred
0.68
.;.;.;Loss of catalytic residue at G20086 (P = 0.0447);.;.;Loss of catalytic residue at G20086 (P = 0.0447);
MVP
0.44
MPC
0.46
ClinPred
0.23
T
GERP RS
6.0

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs756099303; hg19: chr2-179449099; COSMIC: COSV104643553; COSMIC: COSV104643553; API