rs187366691

Variant summary

Our verdict is Benign. Variant got -17 ACMG points: 0P and 17B. BP4_StrongBP6_Very_StrongBP7BS1

The NM_001267550.2(TTN):​c.55449C>T​(p.Pro18483=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000183 in 1,611,550 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. P18483P) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00035 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00017 ( 1 hom. )

Consequence

TTN
NM_001267550.2 synonymous

Scores

2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:12

Conservation

PhyloP100: 0.333
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]

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -17 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.49).
BP6
Variant 2-178601548-G-A is Benign according to our data. Variant chr2-178601548-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 167778.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BP7
Synonymous conserved (PhyloP=0.333 with no splicing effect.
BS1
Variant frequency is greater than expected in population amr. gnomad4_exome allele frequency = 0.000165 (241/1459412) while in subpopulation AMR AF= 0.00495 (221/44642). AF 95% confidence interval is 0.00442. There are 1 homozygotes in gnomad4_exome. There are 105 alleles in male gnomad4_exome subpopulation. Median coverage is 32. This position pass quality control queck.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
TTNNM_001267550.2 linkuse as main transcriptc.55449C>T p.Pro18483= synonymous_variant 287/363 ENST00000589042.5
TTN-AS1NR_038272.1 linkuse as main transcriptn.3917+881G>A intron_variant, non_coding_transcript_variant

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
TTNENST00000589042.5 linkuse as main transcriptc.55449C>T p.Pro18483= synonymous_variant 287/3635 NM_001267550.2 P1
TTN-AS1ENST00000659121.1 linkuse as main transcriptn.502+3867G>A intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes
AF:
0.000355
AC:
54
AN:
152020
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00348
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:
0.000478
GnomAD3 exomes
AF:
0.000713
AC:
176
AN:
246890
Hom.:
1
AF XY:
0.000598
AC XY:
80
AN XY:
133880
show subpopulations
Gnomad AFR exome
AF:
0.0000648
Gnomad AMR exome
AF:
0.00494
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:
0.000835
GnomAD4 exome
AF:
0.000165
AC:
241
AN:
1459412
Hom.:
1
Cov.:
32
AF XY:
0.000145
AC XY:
105
AN XY:
725834
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00495
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:
9.01e-7
Gnomad4 OTH exome
AF:
0.000315
GnomAD4 genome
AF:
0.000355
AC:
54
AN:
152138
Hom.:
0
Cov.:
32
AF XY:
0.000430
AC XY:
32
AN XY:
74350
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00347
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:
0.000473
Alfa
AF:
0.0000280
Hom.:
0
Bravo
AF:
0.00105

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:12
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:4
Likely benign, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Nov 29, 2016- -
Likely benign, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineMar 19, 2012p.Pro15915Pro in Exon 236 of TTN: This variant is not expected to have clinical significance because it does not alter an amino acid residue, is not located wit hin the splice consensus sequence. It has been identified in 1/3080 African Amer ican chromosomes from a broad population by the NHLBI Exome Sequencing Project ( http://evs.gs.washington.edu/EVS;). -
Benign, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpMay 23, 2021- -
Benign, criteria provided, single submitterclinical testingAthena DiagnosticsJul 13, 2020- -
not provided Benign:2
Benign, criteria provided, single submitterclinical testingARUP Laboratories, Molecular Genetics and Genomics, ARUP LaboratoriesSep 11, 2023- -
Likely benign, criteria provided, single submitterclinical testingGeneDxMay 20, 2021- -
Autosomal recessive limb-girdle muscular dystrophy type 2J Benign:1
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
Benign, criteria provided, single submitterclinical testingInvitaeJan 26, 2024- -
Early-onset myopathy with fatal cardiomyopathy Benign:1
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Tibial muscular dystrophy Benign:1
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Myopathy, myofibrillar, 9, with early respiratory failure Benign:1
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Cardiovascular phenotype Benign:1
Likely benign, criteria provided, single submitterclinical testingAmbry GeneticsJan 07, 2020This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.49
CADD
Benign
1.5
DANN
Benign
0.87

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: rs187366691; hg19: chr2-179466275; COSMIC: COSV60335299; COSMIC: COSV60335299; API