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rs768420352

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 5P and 1B. PM1PM2PP2BP4

The NM_001267550.2(TTN):c.94187A>C(p.Glu31396Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000249 in 1,609,152 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 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

3
5
8

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 8.02
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 4 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 4 uncertain in NM_001267550.2
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant where missense usually causes diseases, TTN
BP4
Computational evidence support a benign effect (MetaRNN=0.304035).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
TTNNM_001267550.2 linkuse as main transcriptc.94187A>C p.Glu31396Ala missense_variant 339/363 ENST00000589042.5
TTN-AS1NR_038272.1 linkuse as main transcriptn.2043+5078T>G intron_variant, non_coding_transcript_variant

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
TTNENST00000589042.5 linkuse as main transcriptc.94187A>C p.Glu31396Ala missense_variant 339/3635 NM_001267550.2 P1
TTN-AS1ENST00000659121.1 linkuse as main transcriptn.416+23803T>G intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152218
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:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00000826
AC:
2
AN:
242216
Hom.:
0
AF XY:
0.00000761
AC XY:
1
AN XY:
131434
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000593
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:
0.00000206
AC:
3
AN:
1456934
Hom.:
0
Cov.:
34
AF XY:
0.00000138
AC XY:
1
AN XY:
724198
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000678
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:
0.00
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152218
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74350
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:
0.00000378
ExAC
AF:
0.0000166
AC:
2

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingInvitaeOct 26, 2017- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.23
BayesDel_addAF
Benign
-0.095
T
BayesDel_noAF
Benign
-0.19
Cadd
Benign
20
Dann
Benign
0.94
Eigen
Pathogenic
0.74
Eigen_PC
Pathogenic
0.78
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.92
D;D;D;.;D;D;D
M_CAP
Benign
0.033
D
MetaRNN
Benign
0.30
T;T;T;T;T;T;T
MetaSVM
Benign
-0.33
T
MutationTaster
Benign
1.0
D;D;D;D;D;D
PrimateAI
Uncertain
0.55
T
PROVEAN
Uncertain
-4.3
D;D;.;.;D;D;.
REVEL
Uncertain
0.33
Sift
Uncertain
0.013
D;D;.;.;D;D;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.48
MutPred
0.28
.;.;.;Loss of disorder (P = 0.0613);.;.;Loss of disorder (P = 0.0613);
MVP
0.53
MPC
0.47
ClinPred
0.25
T
GERP RS
6.0

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: rs768420352; hg19: chr2-179412166; API