rs202017608

Variant summary

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

The NM_001267550.2(TTN):​c.59943C>A​(p.Pro19981=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00116 in 1,610,950 control chromosomes in the GnomAD database, including 21 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. P19981P) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00078 ( 1 hom., cov: 32)
Exomes 𝑓: 0.0012 ( 20 hom. )

Consequence

TTN
NM_001267550.2 synonymous

Scores

2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:21

Conservation

PhyloP100: -0.0570
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=-0.55).
BP6
Variant 2-178591876-G-T is Benign according to our data. Variant chr2-178591876-G-T is described in ClinVar as [Likely_benign]. Clinvar id is 47156.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178591876-G-T is described in Lovd as [Benign]. Variant chr2-178591876-G-T is described in Lovd as [Likely_benign].
BP7
Synonymous conserved (PhyloP=-0.057 with no splicing effect.
BS1
Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.000775 (118/152170) while in subpopulation SAS AF= 0.00996 (48/4818). AF 95% confidence interval is 0.00772. There are 1 homozygotes in gnomad4. There are 65 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
BS2
High Homozygotes in GnomAdExome4 at 20 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
TTNNM_001267550.2 linkuse as main transcriptc.59943C>A p.Pro19981= synonymous_variant 303/363 ENST00000589042.5
TTN-AS1NR_038272.1 linkuse as main transcriptn.3364+562G>T intron_variant, non_coding_transcript_variant

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
TTNENST00000589042.5 linkuse as main transcriptc.59943C>A p.Pro19981= synonymous_variant 303/3635 NM_001267550.2 P1
TTN-AS1ENST00000659121.1 linkuse as main transcriptn.417-5720G>T intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes
AF:
0.000769
AC:
117
AN:
152052
Hom.:
1
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000656
Gnomad ASJ
AF:
0.0101
Gnomad EAS
AF:
0.000194
Gnomad SAS
AF:
0.00975
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00633
Gnomad NFE
AF:
0.000265
Gnomad OTH
AF:
0.00144
GnomAD3 exomes
AF:
0.00244
AC:
598
AN:
245216
Hom.:
6
AF XY:
0.00306
AC XY:
406
AN XY:
132896
show subpopulations
Gnomad AFR exome
AF:
0.000130
Gnomad AMR exome
AF:
0.00101
Gnomad ASJ exome
AF:
0.0106
Gnomad EAS exome
AF:
0.0000566
Gnomad SAS exome
AF:
0.0128
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000512
Gnomad OTH exome
AF:
0.00303
GnomAD4 exome
AF:
0.00120
AC:
1755
AN:
1458780
Hom.:
20
Cov.:
35
AF XY:
0.00159
AC XY:
1157
AN XY:
725546
show subpopulations
Gnomad4 AFR exome
AF:
0.000211
Gnomad4 AMR exome
AF:
0.000861
Gnomad4 ASJ exome
AF:
0.0103
Gnomad4 EAS exome
AF:
0.0000253
Gnomad4 SAS exome
AF:
0.0121
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.000230
Gnomad4 OTH exome
AF:
0.00191
GnomAD4 genome
AF:
0.000775
AC:
118
AN:
152170
Hom.:
1
Cov.:
32
AF XY:
0.000874
AC XY:
65
AN XY:
74366
show subpopulations
Gnomad4 AFR
AF:
0.0000241
Gnomad4 AMR
AF:
0.000655
Gnomad4 ASJ
AF:
0.0101
Gnomad4 EAS
AF:
0.000195
Gnomad4 SAS
AF:
0.00996
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000265
Gnomad4 OTH
AF:
0.00142
Alfa
AF:
0.00136
Hom.:
1
Bravo
AF:
0.000665
Asia WGS
AF:
0.00318
AC:
11
AN:
3478
EpiCase
AF:
0.000655
EpiControl
AF:
0.000890

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:21
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:5
Benign, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Dec 23, 2014- -
Benign, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineMar 11, 2015Pro17413Pro in exon 252 of TTN: This variant is not expected to have clinical si gnificance because it has been identified in 1.3% (222/16506) of South Asian chr omosomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.o rg). -
Benign, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpNov 21, 2021- -
Benign, no assertion criteria providedclinical testingGenome Diagnostics Laboratory, University Medical Center Utrecht-- -
Benign, no assertion criteria providedclinical testingClinical Genetics, Academic Medical Center-- -
not provided Benign:4
Benign, criteria provided, single submitterclinical testingGeneDxMar 03, 2015- -
Likely benign, no assertion criteria providedclinical testingDiagnostic Laboratory, Department of Genetics, University Medical Center Groningen-- -
Benign, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenJun 01, 2024TTN: BP4, BP7, BS1, BS2 -
Likely benign, no assertion criteria providedclinical testingClinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center-- -
Autosomal recessive limb-girdle muscular dystrophy type 2J Benign:2
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. -
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 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. -
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Tibial muscular dystrophy Benign:2
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. -
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 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. -
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
Benign, criteria provided, single submitterclinical testingInvitaeJan 31, 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. -
Cardiomyopathy Benign:1
Benign, criteria provided, single submitterclinical testingCHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern OntarioMay 02, 2016- -
Cardiovascular phenotype Benign:1
Likely benign, criteria provided, single submitterclinical testingAmbry GeneticsDec 06, 2012This alteration is classified as likely benign based on a combination of the following: 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
-0.55
CADD
Benign
0.44
DANN
Benign
0.78

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs202017608; hg19: chr2-179456603; API