rs375401971

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4BP6

The NM_001267550.2(TTN):​c.63181C>T​(p.Pro21061Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000787 in 1,524,202 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 Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000051 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

5
4
8

Clinical Significance

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

Conservation

PhyloP100: 7.99

Publications

2 publications found
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 was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.27934805).
BP6
Variant 2-178588544-G-A is Benign according to our data. Variant chr2-178588544-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 47192.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.63181C>T p.Pro21061Ser missense_variant Exon 304 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.63181C>T p.Pro21061Ser missense_variant Exon 304 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
151882
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000121
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
GnomAD2 exomes
AF:
0.0000168
AC:
3
AN:
178718
AF XY:
0.0000106
show subpopulations
Gnomad AFR exome
AF:
0.000205
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS 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:
0.00000510
AC:
7
AN:
1372320
Hom.:
0
Cov.:
32
AF XY:
0.00000445
AC XY:
3
AN XY:
673568
show subpopulations
African (AFR)
AF:
0.000230
AC:
7
AN:
30410
American (AMR)
AF:
0.00
AC:
0
AN:
29756
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
20302
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39052
South Asian (SAS)
AF:
0.00
AC:
0
AN:
68862
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
50094
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5344
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1072058
Other (OTH)
AF:
0.00
AC:
0
AN:
56442
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.461
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000329
AC:
5
AN:
151882
Hom.:
0
Cov.:
33
AF XY:
0.0000405
AC XY:
3
AN XY:
74156
show subpopulations
African (AFR)
AF:
0.000121
AC:
5
AN:
41364
American (AMR)
AF:
0.00
AC:
0
AN:
15222
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5144
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4810
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10598
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67958
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000658
Hom.:
0
Bravo
AF:
0.0000567
ESP6500AA
AF:
0.000805
AC:
3
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000167
AC:
2

ClinVar

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

Submissions by phenotype

not specified Uncertain:1
Mar 06, 2013
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The Pro18493Ser variant in TTN has not been reported in the literature nor previ ously identified by our laboratory. This variant has been identified in 3/3726 A frican American chromosomes from a broad population by the NHLBI Exome Sequencin g Project (http://evs.gs.washington.edu/EVS/). Computational analyses (biochemic al amino acid properties, conservation, AlignGVGD, PolyPhen2, and SIFT) suggest that the Pro18493Ser variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In summary, additional informa tion is needed to fully assess the clinical significance of the Pro18493Ser vari ant. -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1838244:Tibial muscular dystrophy;C1858763:Dilated cardiomyopathy 1G;C1861065:Hypertrophic cardiomyopathy 9;C1863599:Myopathy, myofibrillar, 9, with early respiratory failure;C2673677:Early-onset myopathy with fatal cardiomyopathy Uncertain:1
Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Jun 21, 2021
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Benign:1
Mar 23, 2020
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This 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
AlphaMissense
Benign
0.30
BayesDel_addAF
Benign
-0.24
T
BayesDel_noAF
Benign
-0.30
CADD
Benign
22
DANN
Benign
0.93
Eigen
Pathogenic
0.94
Eigen_PC
Pathogenic
0.94
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.93
D;D;D;.;D;D;D
M_CAP
Benign
0.013
T
MetaRNN
Benign
0.28
T;T;T;T;T;T;T
MetaSVM
Benign
-0.55
T
MutationAssessor
Pathogenic
3.1
.;.;.;M;.;.;M
PhyloP100
8.0
PrimateAI
Uncertain
0.66
T
PROVEAN
Pathogenic
-6.3
D;D;.;.;D;D;.
REVEL
Uncertain
0.33
Sift
Uncertain
0.011
D;D;.;.;D;D;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.37
MVP
0.27
MPC
0.46
ClinPred
0.26
T
GERP RS
6.2
Mutation Taster
=67/33
polymorphism

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

Other links and lift over

dbSNP: rs375401971; hg19: chr2-179453271; API