rs138968178

Variant summary

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

The NM_001267550.2(TTN):​c.98499C>T​(p.Leu32833=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00222 in 1,613,746 control chromosomes in the GnomAD database, including 53 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0018 ( 5 hom., cov: 32)
Exomes 𝑓: 0.0023 ( 48 hom. )

Consequence

TTN
NM_001267550.2 synonymous

Scores

2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:23

Conservation

PhyloP100: -0.335
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]

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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 2-178539566-G-A is Benign according to our data. Variant chr2-178539566-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 47603.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178539566-G-A is described in Lovd as [Benign]. Variant chr2-178539566-G-A is described in Lovd as [Likely_benign].
BP7
Synonymous conserved (PhyloP=-0.335 with no splicing effect.
BS1
Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.00183 (279/152158) while in subpopulation SAS AF= 0.0235 (113/4804). AF 95% confidence interval is 0.02. There are 5 homozygotes in gnomad4. There are 156 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
BS2
High Homozygotes in GnomAd4 at 5 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
TTNNM_001267550.2 linkuse as main transcriptc.98499C>T p.Leu32833= synonymous_variant 352/363 ENST00000589042.5
TTN-AS1NR_038272.1 linkuse as main transcriptn.1516G>A non_coding_transcript_exon_variant 5/17

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
TTNENST00000589042.5 linkuse as main transcriptc.98499C>T p.Leu32833= synonymous_variant 352/3635 NM_001267550.2 P1
TTN-AS1ENST00000659121.1 linkuse as main transcriptn.416+15930G>A intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes
AF:
0.00182
AC:
276
AN:
152040
Hom.:
4
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000386
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00183
Gnomad ASJ
AF:
0.000864
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.0229
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00169
Gnomad OTH
AF:
0.00191
GnomAD3 exomes
AF:
0.00376
AC:
936
AN:
248754
Hom.:
13
AF XY:
0.00480
AC XY:
647
AN XY:
134914
show subpopulations
Gnomad AFR exome
AF:
0.000323
Gnomad AMR exome
AF:
0.000782
Gnomad ASJ exome
AF:
0.00159
Gnomad EAS exome
AF:
0.000111
Gnomad SAS exome
AF:
0.0217
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00178
Gnomad OTH exome
AF:
0.00348
GnomAD4 exome
AF:
0.00227
AC:
3311
AN:
1461588
Hom.:
48
Cov.:
33
AF XY:
0.00289
AC XY:
2100
AN XY:
727084
show subpopulations
Gnomad4 AFR exome
AF:
0.000717
Gnomad4 AMR exome
AF:
0.000693
Gnomad4 ASJ exome
AF:
0.00126
Gnomad4 EAS exome
AF:
0.000227
Gnomad4 SAS exome
AF:
0.0211
Gnomad4 FIN exome
AF:
0.0000749
Gnomad4 NFE exome
AF:
0.00106
Gnomad4 OTH exome
AF:
0.00298
GnomAD4 genome
AF:
0.00183
AC:
279
AN:
152158
Hom.:
5
Cov.:
32
AF XY:
0.00210
AC XY:
156
AN XY:
74382
show subpopulations
Gnomad4 AFR
AF:
0.000385
Gnomad4 AMR
AF:
0.00183
Gnomad4 ASJ
AF:
0.000864
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.0235
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00169
Gnomad4 OTH
AF:
0.00189
Alfa
AF:
0.00125
Hom.:
1
Bravo
AF:
0.00111
Asia WGS
AF:
0.0130
AC:
45
AN:
3478
EpiCase
AF:
0.00278
EpiControl
AF:
0.00243

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:23
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:7
Benign, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Sep 03, 2015- -
Benign, criteria provided, single submitterclinical testingAthena DiagnosticsNov 04, 2019- -
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, no assertion criteria providedclinical testingClinical Genetics, Academic Medical Center-- -
Benign, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineApr 28, 2015p.Leu30265Leu in exon 301 of TTN: This variant is not expected to have clinical significance because it has been identified in 2.3% (384/16510) of South Asian c hromosomes, including 7 homozygotes, by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; dbSNP rs138968178). -
Benign, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpJan 06, 2020- -
Benign, no assertion criteria providedclinical testingJoint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+-- -
not provided Benign:4
Benign, criteria provided, single submitterclinical testingARUP Laboratories, Molecular Genetics and Genomics, ARUP LaboratoriesMar 12, 2020- -
Likely benign, no assertion criteria providedclinical testingClinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center-- -
Likely benign, no assertion criteria providedclinical testingDiagnostic Laboratory, Department of Genetics, University Medical Center Groningen-- -
Likely benign, no assertion criteria providedclinical testingLaboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)-- -
Autosomal recessive limb-girdle muscular dystrophy type 2J Benign:2
Likely benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 13, 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. -
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Early-onset myopathy with fatal cardiomyopathy Benign:2
Likely benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 13, 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. -
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Myopathy, myofibrillar, 9, with early respiratory failure Benign:2
Benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 13, 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. -
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Tibial muscular dystrophy Benign:2
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 13, 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 testingInvitaeJan 31, 2024- -
Cardiomyopathy Benign:1
Benign, criteria provided, single submitterclinical testingCHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern OntarioMay 30, 2019- -
Dilated cardiomyopathy 1G Benign:1
Likely benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 13, 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. -
Cardiovascular phenotype Benign:1
Benign, criteria provided, single submitterclinical testingAmbry GeneticsJan 06, 2016This alteration is classified as 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
BayesDel_noAF
Benign
-0.51
CADD
Benign
0.0090
DANN
Benign
0.83

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

LitVar

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

Other links and lift over

dbSNP: rs138968178; hg19: chr2-179404293; COSMIC: COSV60165045; COSMIC: COSV60165045; API