NM_133379.5:c.14526T>A

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4_StrongBS1_Supporting

The NM_133379.5(TTN):​c.14526T>A​(p.Asn4842Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000101 in 1,612,832 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 12/15 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 0.000040 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00011 ( 1 hom. )

Consequence

TTN
NM_133379.5 missense

Scores

2
13

Clinical Significance

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

Conservation

PhyloP100: 0.572
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.

BP4
Computational evidence support a benign effect (MetaRNN=0.0047519803).
BS1
Variant frequency is greater than expected in population eas. gnomad4_exome allele frequency = 0.000107 (157/1460940) while in subpopulation EAS AF= 0.00366 (145/39632). AF 95% confidence interval is 0.00317. There are 1 homozygotes in gnomad4_exome. There are 74 alleles in male gnomad4_exome subpopulation. Median coverage is 35. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_133379.5 linkc.14526T>A p.Asn4842Lys missense_variant Exon 46 of 46 ENST00000360870.10 NP_596870.2 Q8WZ42-6Q7Z3B7
TTNNM_001267550.2 linkc.11311+5250T>A intron_variant Intron 47 of 362 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000360870.10 linkc.14526T>A p.Asn4842Lys missense_variant Exon 46 of 46 5 NM_133379.5 ENSP00000354117.4 Q8WZ42-6
TTNENST00000589042.5 linkc.11311+5250T>A intron_variant Intron 47 of 362 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.0000395
AC:
6
AN:
151892
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:
0.00116
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:
0.000136
AC:
34
AN:
249820
Hom.:
2
AF XY:
0.000118
AC XY:
16
AN XY:
135092
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00186
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:
0.000107
AC:
157
AN:
1460940
Hom.:
1
Cov.:
35
AF XY:
0.000102
AC XY:
74
AN XY:
726786
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00366
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
9.00e-7
Gnomad4 OTH exome
AF:
0.000166
GnomAD4 genome
AF:
0.0000395
AC:
6
AN:
151892
Hom.:
0
Cov.:
32
AF XY:
0.0000405
AC XY:
3
AN XY:
74158
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00116
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000868
Hom.:
0
Bravo
AF:
0.0000416
ExAC
AF:
0.000198
AC:
24
Asia WGS
AF:
0.00173
AC:
6
AN:
3478

ClinVar

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

Submissions by phenotype

not provided Uncertain:2
Feb 23, 2017
Eurofins Ntd Llc (ga)
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Jun 24, 2013
Biesecker Lab/Clinical Genomics Section, National Institutes of Health
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: research

- -

not specified Uncertain:1Benign:1
Feb 16, 2015
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

p.Asn4842Lys variant in exon 45A of TTN: This variant is not expected to have cl inical significance because it has been identified in 0.3% (24/8532) of East Asi an chromosomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinsti tute.org). -

Apr 15, 2014
GeneDx
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Missense variants in the TTN gene are considered 'unclassified' if they are not previously reported in the literature and do not have >1% frequency in the population to be considered a polymorphism. Research indicates that truncating mutations in the TTN gene are expected to account for approximately 25% of familial and 18% of sporadic idiopathic DCM; however, truncating variants in the TTN gene have been reported in approximately 3% of reported control alleles. There has been little investigation into non-truncating variants. (Herman D et al. Truncations of titin causing dilated cardiomyopathy. N Eng J Med 366:619-628, 2012) The variant is found in CARDIOMYOPATHY panel(s). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Benign
-0.62
T
BayesDel_noAF
Benign
-0.67
CADD
Benign
13
DANN
Uncertain
0.98
Eigen
Benign
-0.85
Eigen_PC
Benign
-0.76
FATHMM_MKL
Benign
0.089
N
LIST_S2
Benign
0.41
T
M_CAP
Benign
0.020
T
MetaRNN
Benign
0.0048
T
MetaSVM
Benign
-1.0
T
PROVEAN
Benign
-0.42
N
REVEL
Benign
0.036
Sift
Uncertain
0.015
D
Sift4G
Benign
1.0
T
Polyphen
0.0
B
Vest4
0.067
MutPred
0.22
Gain of ubiquitination at N4842 (P = 0.0022);
MVP
0.13
ClinPred
0.023
T
GERP RS
3.4

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: rs776361113; hg19: chr2-179612601; API