rs149375775

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_StrongBP6BS1

The NM_001267550.2(TTN):​c.94283G>A​(p.Arg31428His) variant causes a missense change. The variant allele was found at a frequency of 0.000171 in 1,613,786 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R31428G) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00094 ( 1 hom., cov: 32)
Exomes 𝑓: 0.000091 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

1
7
9

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:12

Conservation

PhyloP100: 6.00

Publications

3 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 -9 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.016452104).
BP6
Variant 2-178547242-C-T is Benign according to our data. Variant chr2-178547242-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 96315.
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000939 (143/152290) while in subpopulation AFR AF = 0.00325 (135/41566). AF 95% confidence interval is 0.0028. There are 1 homozygotes in GnomAd4. There are 69 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.94283G>A p.Arg31428His missense_variant Exon 340 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.94283G>A p.Arg31428His missense_variant Exon 340 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.000874
AC:
133
AN:
152172
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00302
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
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:
0.0000441
Gnomad OTH
AF:
0.00144
GnomAD2 exomes
AF:
0.000213
AC:
53
AN:
248620
AF XY:
0.000171
show subpopulations
Gnomad AFR exome
AF:
0.00239
Gnomad AMR exome
AF:
0.000232
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000557
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000444
Gnomad OTH exome
AF:
0.000332
GnomAD4 exome
AF:
0.0000910
AC:
133
AN:
1461496
Hom.:
1
Cov.:
34
AF XY:
0.0000743
AC XY:
54
AN XY:
727032
show subpopulations
African (AFR)
AF:
0.00254
AC:
85
AN:
33464
American (AMR)
AF:
0.000201
AC:
9
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26124
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39692
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53398
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5764
European-Non Finnish (NFE)
AF:
0.0000225
AC:
25
AN:
1111718
Other (OTH)
AF:
0.000182
AC:
11
AN:
60364
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.483
Heterozygous variant carriers
0
12
24
36
48
60
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
4
8
12
16
20
<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:
0.000939
AC:
143
AN:
152290
Hom.:
1
Cov.:
32
AF XY:
0.000927
AC XY:
69
AN XY:
74462
show subpopulations
African (AFR)
AF:
0.00325
AC:
135
AN:
41566
American (AMR)
AF:
0.000131
AC:
2
AN:
15292
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5178
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68018
Other (OTH)
AF:
0.00142
AC:
3
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.498
Heterozygous variant carriers
0
8
16
25
33
41
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:
0.000485
Hom.:
0
Bravo
AF:
0.00102
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.00
AC:
0
ESP6500AA
AF:
0.00262
AC:
10
ESP6500EA
AF:
0.000121
AC:
1
ExAC
AF:
0.000281
AC:
34
Asia WGS
AF:
0.000577
AC:
2
AN:
3478
EpiCase
AF:
0.000109
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:12
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not specified Benign:6
Mar 19, 2012
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Arg28860His in exon 289 of TTN: This variant is not expected to have clinical si gnificance because it has been identified in 0.3% (10/3126) of African American chromosomes by the NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/ EVS; dbSNP rs149375775). Arg28860His in exon 289 of TTN (rs149375775; allele f requency = 0.3%, 10/3126) ** -

Mar 12, 2013
Eurofins Ntd Llc (ga)
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

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

- -

Feb 06, 2018
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Nov 15, 2021
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: TTN c.86579G>A (p.Arg28860His) results in a non-conservative amino acid change located in the A-Band region of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00021 in 248620 control chromosomes, predominantly at a frequency of 0.0024 within the African or African-American subpopulation in the gnomAD database. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 4-fold of the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Cardiomyopathy phenotype (0.00063), 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.86579G>A in individuals affected with Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and all laboratories classified the variant as likely benign. Based on the evidence outlined above, the variant was classified as likely benign. -

-
Clinical Genetics, Academic Medical Center
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

not provided Uncertain:1Benign:3
-
Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Sep 28, 2023
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jun 01, 2022
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

TTN: BS1 -

Oct 26, 2023
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

TTN-related disorder Benign:1
Apr 01, 2021
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
Feb 02, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Benign:1
Oct 04, 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
0.10
BayesDel_addAF
Benign
-0.33
T
BayesDel_noAF
Benign
-0.25
CADD
Benign
22
DANN
Benign
0.97
Eigen
Uncertain
0.68
Eigen_PC
Pathogenic
0.72
FATHMM_MKL
Uncertain
0.92
D
LIST_S2
Uncertain
0.93
D;D;D;.;D;D;D
M_CAP
Benign
0.027
D
MetaRNN
Benign
0.016
T;T;T;T;T;T;T
MetaSVM
Benign
-0.65
T
MutationAssessor
Benign
0.54
.;.;.;N;.;.;N
PhyloP100
6.0
PrimateAI
Uncertain
0.59
T
PROVEAN
Uncertain
-3.6
D;D;.;.;D;D;.
REVEL
Uncertain
0.37
Sift
Uncertain
0.015
D;D;.;.;D;D;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.48
MVP
0.35
MPC
0.50
ClinPred
0.025
T
GERP RS
6.0
Mutation Taster
=84/16
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: rs149375775; hg19: chr2-179411969; API