rs147580753

Variant summary

Our verdict is Benign. The variant received -13 ACMG points: 0P and 13B. BP4_StrongBP6BS1BS2

The NM_001267550.2(TTN):​c.61322A>G​(p.Asn20441Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000194 in 1,606,986 control chromosomes in the GnomAD database, including 3 homozygotes. In-silico tool predicts a benign outcome for this variant. 15/20 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: š‘“ 0.0011 ( 2 hom., cov: 33)
Exomes š‘“: 0.00010 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

4
13

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:8

Conservation

PhyloP100: 1.85

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: Benign. The variant received -13 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.0068585575).
BP6
Variant 2-178590403-T-C is Benign according to our data. Variant chr2-178590403-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 47172.
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00108 (165/152200) while in subpopulation AFR AF = 0.0039 (162/41566). AF 95% confidence interval is 0.00341. There are 2 homozygotes in GnomAd4. There are 74 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.
BS2
High Homozygotes in GnomAd4 at 2 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.61322A>G p.Asn20441Ser missense_variant Exon 304 of 363 ENST00000589042.5 NP_001254479.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.61322A>G p.Asn20441Ser missense_variant Exon 304 of 363 5 NM_001267550.2 ENSP00000467141.1

Frequencies

GnomAD3 genomes
AF:
0.00108
AC:
165
AN:
152082
Hom.:
2
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00391
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000197
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:
0.000260
AC:
63
AN:
241882
AF XY:
0.000176
show subpopulations
Gnomad AFR exome
AF:
0.00357
Gnomad AMR exome
AF:
0.000178
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000182
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000101
AC:
147
AN:
1454786
Hom.:
1
Cov.:
37
AF XY:
0.0000940
AC XY:
68
AN XY:
723040
show subpopulations
African (AFR)
AF:
0.00385
AC:
128
AN:
33248
American (AMR)
AF:
0.000159
AC:
7
AN:
44042
Ashkenazi Jewish (ASJ)
AF:
0.0000391
AC:
1
AN:
25600
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39546
South Asian (SAS)
AF:
0.0000118
AC:
1
AN:
84432
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53064
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5708
European-Non Finnish (NFE)
AF:
9.02e-7
AC:
1
AN:
1109084
Other (OTH)
AF:
0.000150
AC:
9
AN:
60062
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.479
Heterozygous variant carriers
0
10
20
30
40
50
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.00108
AC:
165
AN:
152200
Hom.:
2
Cov.:
33
AF XY:
0.000995
AC XY:
74
AN XY:
74396
show subpopulations
African (AFR)
AF:
0.00390
AC:
162
AN:
41566
American (AMR)
AF:
0.000196
AC:
3
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5144
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4820
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10630
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67976
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
7
13
20
26
33
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
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:
0.000562
Hom.:
2
Bravo
AF:
0.00120
ESP6500AA
AF:
0.00261
AC:
10
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.000397
AC:
48

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:8
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2Benign:2
Nov 06, 2023
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jul 27, 2020
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 07, 2014
Genetic Services Laboratory, University of Chicago
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 27, 2017
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Benign:3
May 09, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: TTN c.53618A>G (p.Asn17873Ser) results in a conservative amino acid change located in the A-band region of the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00035 in 273254 control chromosomes (gnomAD), predominantly at a frequency of 0.0037 within the African or African-American subpopulation in the gnomAD database, including 2 homozygotes. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 9 fold of the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Dilated Cardiomyopathy phenotype (0.00039), strongly suggesting that the variant is a benign polymorphism found primarily in populations of African or African-American origin. To our knowledge, no occurrence of c.53618A>G in individuals affected with Dilated Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. Five ClinVar submitters have assessed the variant since 2014: two classify the variant as of uncertain significance and three as likely benign. Based on the evidence outlined above, the variant was classified as benign. -

Feb 22, 2013
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Asn17873Ser in exon 253 of TTN: This variant is not expected to have clinical si gnificance because it has been identified in 0.3% (10/3832) of African American chromosomes from a broad population by the NHLBI Exome Sequencing Project (http: //evs.gs.washington.edu/EVS/; dbSNP rs147580753) and in 1/176 chromosomes from a population of Yoruba individuals by the 1000 Genomes project (dbSNP rs147580753 ). Asn17873Ser in exon 253 of TTN (rs147580753; allele frequency = 0.3%, 10/38 32) ** -

Apr 09, 2025
Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

TTN-related disorder Benign:1
Mar 10, 2020
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
Jan 28, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Benign:1
Aug 02, 2018
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
0.081
BayesDel_addAF
Benign
-0.54
T
BayesDel_noAF
Benign
-0.54
CADD
Benign
15
DANN
Benign
0.82
Eigen
Benign
-0.21
Eigen_PC
Benign
-0.044
FATHMM_MKL
Uncertain
0.89
D
LIST_S2
Uncertain
0.91
D;D;D;.;D;D;D
M_CAP
Benign
0.017
T
MetaRNN
Benign
0.0069
T;T;T;T;T;T;T
MetaSVM
Benign
-0.94
T
MutationAssessor
Benign
0.69
.;.;.;N;.;.;N
PhyloP100
1.8
PrimateAI
Uncertain
0.52
T
PROVEAN
Uncertain
-2.6
D;D;.;.;D;D;.
REVEL
Benign
0.13
Sift
Benign
0.79
T;T;.;.;T;T;.
Polyphen
0.10
.;.;.;B;.;.;B
Vest4
0.23
MVP
0.14
MPC
0.096
ClinPred
0.032
T
GERP RS
3.6
Mutation Taster
=94/6
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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: rs147580753; hg19: chr2-179455130; API