GeneBe

rs775508685

Positions:

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 2P and 7B. PM2BP4_StrongBP6_ModerateBP7

The NM_001267550.2(TTN):​c.23100A>T​(p.Ala7700=) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000127 in 1,572,566 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 7.0e-7 ( 0 hom. )

Consequence

TTN
NM_001267550.2 splice_region, synonymous

Scores

2
Splicing: ADA: 0.00001957
2

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: 0.707
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 Likely_benign. Variant got -5 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.48).
BP6
Variant 2-178720662-T-A is Benign according to our data. Variant chr2-178720662-T-A is described in ClinVar as [Likely_benign]. Clinvar id is 466918.Status of the report is criteria_provided_single_submitter, 1 stars.
BP7
Synonymous conserved (PhyloP=0.707 with no splicing effect.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
TTNNM_001267550.2 linkuse as main transcriptc.23100A>T p.Ala7700= splice_region_variant, synonymous_variant 80/363 ENST00000589042.5 NP_001254479.2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkuse as main transcriptc.23100A>T p.Ala7700= splice_region_variant, synonymous_variant 80/3635 NM_001267550.2 ENSP00000467141 P1
TTN-AS1ENST00000659121.1 linkuse as main transcriptn.503-13842T>A intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes
AF:
0.00000660
AC:
1
AN:
151572
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000243
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00000476
AC:
1
AN:
210226
Hom.:
0
AF XY:
0.00000872
AC XY:
1
AN XY:
114724
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
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:
0.00000995
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
7.04e-7
AC:
1
AN:
1420994
Hom.:
0
Cov.:
35
AF XY:
0.00000142
AC XY:
1
AN XY:
704482
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
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:
9.11e-7
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000660
AC:
1
AN:
151572
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
73982
show subpopulations
Gnomad4 AFR
AF:
0.0000243
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:
0.00
Gnomad4 OTH
AF:
0.00

ClinVar

Significance: Likely benign
Submissions summary: Benign:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
Likely benign, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJan 17, 2024- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.48
CADD
Benign
3.8
DANN
Benign
0.59

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.000020
dbscSNV1_RF
Benign
0.0
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: rs775508685; hg19: chr2-179585389; API