rs116378128

Variant summary

Our verdict is Benign. Variant got -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2

The NM_001267550.2(TTN):​c.25008C>T​(p.Cys8336=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00075 in 1,613,766 control chromosomes in the GnomAD database, including 10 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0039 ( 3 hom., cov: 33)
Exomes 𝑓: 0.00043 ( 7 hom. )

Consequence

TTN
NM_001267550.2 synonymous

Scores

2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:17

Conservation

PhyloP100: 2.63
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 Benign. Variant got -21 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.51).
BP6
Variant 2-178717998-G-A is Benign according to our data. Variant chr2-178717998-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 46747.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178717998-G-A is described in Lovd as [Benign].
BP7
Synonymous conserved (PhyloP=2.63 with no splicing effect.
BS1
Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00387 (589/152288) while in subpopulation AFR AF= 0.0134 (558/41562). AF 95% confidence interval is 0.0125. There are 3 homozygotes in gnomad4. There are 292 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.
BS2
High Homozygotes in GnomAd4 at 3 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
TTNNM_001267550.2 linkuse as main transcriptc.25008C>T p.Cys8336= synonymous_variant 86/363 ENST00000589042.5 NP_001254479.2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkuse as main transcriptc.25008C>T p.Cys8336= synonymous_variant 86/3635 NM_001267550.2 ENSP00000467141 P1
TTN-AS1ENST00000659121.1 linkuse as main transcriptn.503-16506G>A intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes
AF:
0.00386
AC:
587
AN:
152170
Hom.:
3
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0134
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00137
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:
0.0000735
Gnomad OTH
AF:
0.00239
GnomAD3 exomes
AF:
0.000889
AC:
221
AN:
248574
Hom.:
1
AF XY:
0.000801
AC XY:
108
AN XY:
134830
show subpopulations
Gnomad AFR exome
AF:
0.0132
Gnomad AMR exome
AF:
0.000290
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000267
Gnomad OTH exome
AF:
0.000497
GnomAD4 exome
AF:
0.000426
AC:
622
AN:
1461478
Hom.:
7
Cov.:
35
AF XY:
0.000369
AC XY:
268
AN XY:
727010
show subpopulations
Gnomad4 AFR exome
AF:
0.0151
Gnomad4 AMR exome
AF:
0.000425
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000348
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000225
Gnomad4 OTH exome
AF:
0.00111
GnomAD4 genome
AF:
0.00387
AC:
589
AN:
152288
Hom.:
3
Cov.:
33
AF XY:
0.00392
AC XY:
292
AN XY:
74464
show subpopulations
Gnomad4 AFR
AF:
0.0134
Gnomad4 AMR
AF:
0.00137
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000735
Gnomad4 OTH
AF:
0.00236
Alfa
AF:
0.00174
Hom.:
1
Bravo
AF:
0.00441
Asia WGS
AF:
0.00115
AC:
4
AN:
3478
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:17
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:5
Benign, no assertion criteria providedclinical testingClinical Genetics, Academic Medical Center-- -
Benign, criteria provided, single submitterclinical testingGeneDxApr 29, 2014This 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. -
Benign, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineMar 19, 2012p.Cys7092Cys in Exon 83 of TTN: This variant is not expected to have clinical si gnificance because it does not alter an amino acid residue, is not located withi n the splice consensus sequence and has been identified in 1.1% (37/3360) of Afr ican American chromosomes from a broad population by the NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS; dbSNP rs116378128). -
Benign, no assertion criteria providedclinical testingClinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center-- -
Benign, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpFeb 03, 2020Variant summary: TTN c.21276C>T alters a conserved nucleotide resulting in a synonymous change. Several computational tools predict a significant impact on normal splicing: Two predict the variant creates a 5' donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.00089 in 248574 control chromosomes in the gnomAD database, including 1 homozygotes. The observed variant frequency is approximately 1.4 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 benign. To our knowledge, no occurrence of c.21276C>T 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 without evidence for independent evaluation. Both laboratories classified the variant as benign. Based on the evidence outlined above, the variant was classified as benign. -
Autosomal recessive limb-girdle muscular dystrophy type 2J Benign:2
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Likely benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 12, 2018This 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. -
Early-onset myopathy with fatal cardiomyopathy Benign:2
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Likely benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 12, 2018This 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. -
not provided Benign:2
Benign, criteria provided, single submitterclinical testingAthena DiagnosticsSep 12, 2017- -
Benign, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenApr 01, 2024TTN: BP4, BS1, BS2 -
Tibial muscular dystrophy Benign:2
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 12, 2018This 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:2
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 12, 2018This 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. -
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
Benign, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpFeb 01, 2024- -
Dilated cardiomyopathy 1G Benign:1
Likely benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 12, 2018This 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
BayesDel_noAF
Benign
-0.51
CADD
Benign
8.6
DANN
Benign
0.66

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.070
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: rs116378128; hg19: chr2-179582725; API