rs201029552

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 0P and 3B. BP4_ModerateBP6

The NM_001267550.2(TTN):​c.21656C>T​(p.Ser7219Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000235 in 1,613,046 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/18 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 0.00022 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00024 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

1
15

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:8B:6

Conservation

PhyloP100: 1.18
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 -3 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.108828545).
BP6
Variant 2-178723444-G-A is Benign according to our data. Variant chr2-178723444-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 203300.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=4, Benign=2, Uncertain_significance=8}. Variant chr2-178723444-G-A is described in Lovd as [Likely_benign].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.21656C>T p.Ser7219Phe missense_variant Exon 74 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.21656C>T p.Ser7219Phe missense_variant Exon 74 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.000217
AC:
33
AN:
152166
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000482
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000656
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000828
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000368
Gnomad OTH
AF:
0.000478
GnomAD3 exomes
AF:
0.000266
AC:
66
AN:
247700
Hom.:
0
AF XY:
0.000290
AC XY:
39
AN XY:
134390
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000408
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000560
Gnomad SAS exome
AF:
0.000197
Gnomad FIN exome
AF:
0.0000467
Gnomad NFE exome
AF:
0.000330
Gnomad OTH exome
AF:
0.00117
GnomAD4 exome
AF:
0.000237
AC:
346
AN:
1460762
Hom.:
1
Cov.:
33
AF XY:
0.000252
AC XY:
183
AN XY:
726588
show subpopulations
Gnomad4 AFR exome
AF:
0.0000598
Gnomad4 AMR exome
AF:
0.000537
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000505
Gnomad4 SAS exome
AF:
0.000348
Gnomad4 FIN exome
AF:
0.0000187
Gnomad4 NFE exome
AF:
0.000240
Gnomad4 OTH exome
AF:
0.000315
GnomAD4 genome
AF:
0.000217
AC:
33
AN:
152284
Hom.:
0
Cov.:
33
AF XY:
0.000201
AC XY:
15
AN XY:
74456
show subpopulations
Gnomad4 AFR
AF:
0.0000481
Gnomad4 AMR
AF:
0.0000655
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000829
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000368
Gnomad4 OTH
AF:
0.000473
Alfa
AF:
0.000282
Hom.:
0
Bravo
AF:
0.000246
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.000259
AC:
1
ExAC
AF:
0.000232
AC:
28
Asia WGS
AF:
0.000289
AC:
1
AN:
3476
EpiCase
AF:
0.000437
EpiControl
AF:
0.000356

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:8Benign:6
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2Benign:2
Sep 18, 2020
GeneDx
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Mar 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

TTN: BP4 -

Nov 17, 2016
Eurofins Ntd Llc (ga)
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Mar 10, 2023
Revvity Omics, Revvity
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

not specified Benign:2
Jan 24, 2025
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.17924C>T (p.Ser5975Phe) results in a non-conservative amino acid change in the encoded protein sequence. Two of three in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00027 in 247700 control chromosomes, predominantly at a frequency of 0.00041 within the Latino subpopulation in the gnomAD database. The observed variant frequency within Latino control individuals in the gnomAD database is approximately 1.049 fold of the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Dilated Cardiomyopathy phenotype (0.00039). c.17924C>T has been reported in the literature in an unknown number of individuals (zygosity not provided) in a cohort affected with cardiac conditions, without strong evidence for causality (example Campuzano_2015). These report(s) do not provide unequivocal conclusions about association of the variant with TTN-related conditions. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. ClinVar contains an entry for this variant (Variation ID: 203300). Based on the evidence outlined above, the variant was classified as likely benign. -

May 22, 2019
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The p.Ser5975Phe variant in TTN is classified as likely benign due to a lack of conservation across species. Four mammals (pig, horse, white rhinoceros and elephant) carry a phenylalanine (Phe) at this position despite high nearby amino acid conservation. It has also been identified in 0.04% (14/35192) of Latino chromosomes by gnomAD (http://gnomad.broadinstitute.org). ACMG/AMP Criteria applied: BS1, BP4_Strong. -

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
Jan 04, 2018
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Inborn genetic diseases Uncertain:1
Jun 05, 2014
Ambry Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Lines of evidence used in support of classification: UNCERTAIN: Alteration(s) of Uncertain Clinical Significance Detected -

Cardiomyopathy Uncertain:1
Aug 09, 2016
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
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. -

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. -

Myopathy, myofibrillar, 9, with early respiratory failure Benign:1
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance: Likely 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 likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.16
BayesDel_addAF
Benign
-0.38
T
BayesDel_noAF
Benign
-0.43
CADD
Benign
17
DANN
Benign
0.95
Eigen
Benign
-0.16
Eigen_PC
Benign
-0.11
FATHMM_MKL
Benign
0.25
N
LIST_S2
Benign
0.72
T;T;.;T
M_CAP
Benign
0.055
D
MetaRNN
Benign
0.11
T;T;T;T
MetaSVM
Benign
-0.61
T
PrimateAI
Benign
0.44
T
PROVEAN
Uncertain
-3.5
D;.;.;.
REVEL
Benign
0.16
Sift
Benign
0.075
T;.;.;.
Polyphen
0.0010
.;.;B;B
Vest4
0.34
MVP
0.56
MPC
0.093
ClinPred
0.017
T
GERP RS
4.3

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs201029552; hg19: chr2-179588171; COSMIC: COSV60295073; COSMIC: COSV60295073; API