rs200155485

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6

The NM_001267550.2(TTN):​c.65746C>T​(p.Arg21916Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000683 in 1,610,924 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R21916Q) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000099 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000065 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

1
7
9

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:8B:3

Conservation

PhyloP100: 2.63

Publications

6 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 -3 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.11211395).
BP6
Variant 2-178583057-G-A is Benign according to our data. Variant chr2-178583057-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 165891.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.65746C>T p.Arg21916Trp missense_variant Exon 313 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.65746C>T p.Arg21916Trp missense_variant Exon 313 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.0000987
AC:
15
AN:
151980
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000725
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000197
Gnomad ASJ
AF:
0.00144
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000589
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000114
AC:
28
AN:
244946
AF XY:
0.0000753
show subpopulations
Gnomad AFR exome
AF:
0.0000657
Gnomad AMR exome
AF:
0.0000587
Gnomad ASJ exome
AF:
0.00180
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000452
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000651
AC:
95
AN:
1458944
Hom.:
1
Cov.:
30
AF XY:
0.0000537
AC XY:
39
AN XY:
725628
show subpopulations
African (AFR)
AF:
0.0000599
AC:
2
AN:
33384
American (AMR)
AF:
0.0000449
AC:
2
AN:
44504
Ashkenazi Jewish (ASJ)
AF:
0.00173
AC:
45
AN:
26080
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39368
South Asian (SAS)
AF:
0.0000349
AC:
3
AN:
85944
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53278
Middle Eastern (MID)
AF:
0.000174
AC:
1
AN:
5752
European-Non Finnish (NFE)
AF:
0.0000315
AC:
35
AN:
1110402
Other (OTH)
AF:
0.000116
AC:
7
AN:
60232
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.460
Heterozygous variant carriers
0
5
11
16
22
27
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome 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
GnomAD4 genome
AF:
0.0000987
AC:
15
AN:
151980
Hom.:
0
Cov.:
33
AF XY:
0.000135
AC XY:
10
AN XY:
74212
show subpopulations
African (AFR)
AF:
0.0000725
AC:
3
AN:
41400
American (AMR)
AF:
0.000197
AC:
3
AN:
15264
Ashkenazi Jewish (ASJ)
AF:
0.00144
AC:
5
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5156
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4818
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10590
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000589
AC:
4
AN:
67962
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.455
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.000296
Hom.:
0
Bravo
AF:
0.0000869
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000240
AC:
2
ExAC
AF:
0.000108
AC:
13
Asia WGS
AF:
0.000866
AC:
3
AN:
3478

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:8Benign:3
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:3Benign:1
Jun 24, 2013
Biesecker Lab/Clinical Genomics Section, National Institutes of Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:research

- -

Jun 14, 2023
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mar 14, 2018
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

May 30, 2018
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is associated with the following publications: (PMID: 27321809, 23861362) -

not specified Uncertain:1
Oct 15, 2015
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Arg19348Trp variant in TTN has been identified by our laboratory in 1 indi vidual with HCM. This variant has been identified in 9/63072 European chromosome s by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; dbS NP rs200155485). Computational prediction tools and conservation analysis do not provide strong support for or against an impact to the protein. In summary, the clinical significance of the p.Arg19348Trp variant is uncertain. -

Autosomal recessive limb-girdle muscular dystrophy type 2J Uncertain:1
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Oct 12, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dilated cardiomyopathy 1G Uncertain:1
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Early-onset myopathy with fatal cardiomyopathy Uncertain:1
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Myopathy, myofibrillar, 9, with early respiratory failure Benign:1
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Tibial muscular dystrophy Benign:1
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.30
BayesDel_addAF
Benign
-0.21
T
BayesDel_noAF
Benign
-0.36
CADD
Benign
20
DANN
Benign
0.89
Eigen
Uncertain
0.28
Eigen_PC
Uncertain
0.24
FATHMM_MKL
Uncertain
0.87
D
LIST_S2
Uncertain
0.93
D;D;D;.;D;D;D
M_CAP
Benign
0.050
D
MetaRNN
Benign
0.11
T;T;T;T;T;T;T
MetaSVM
Benign
-0.67
T
MutationAssessor
Benign
1.6
.;.;.;L;.;.;L
PhyloP100
2.6
PrimateAI
Uncertain
0.49
T
PROVEAN
Pathogenic
-5.2
D;D;.;.;D;D;.
REVEL
Uncertain
0.34
Sift
Uncertain
0.0040
D;D;.;.;D;D;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.46
MVP
0.34
MPC
0.45
ClinPred
0.20
T
GERP RS
2.9
Mutation Taster
=93/7
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: rs200155485; hg19: chr2-179447784; COSMIC: COSV60009809; COSMIC: COSV60009809; API