rs56169243

Variant summary

Our verdict is Benign. Variant got -14 ACMG points: 0P and 14B. BP4_StrongBP6BP7BS1BS2

The NM_001267550.2(TTN):ā€‹c.72132T>Cā€‹(p.Gly24044=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0058 in 1,613,340 control chromosomes in the GnomAD database, including 44 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: š‘“ 0.0039 ( 4 hom., cov: 32)
Exomes š‘“: 0.0060 ( 40 hom. )

Consequence

TTN
NM_001267550.2 synonymous

Scores

2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:3B:15

Conservation

PhyloP100: 0.365
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 -14 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.49).
BP6
Variant 2-178574000-A-G is Benign according to our data. Variant chr2-178574000-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 47308.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=5, Likely_pathogenic=1, Benign=9, Uncertain_significance=3}. Variant chr2-178574000-A-G is described in Lovd as [Benign]. Variant chr2-178574000-A-G is described in Lovd as [Likely_benign].
BP7
Synonymous conserved (PhyloP=0.365 with no splicing effect.
BS1
Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.00386 (588/152176) while in subpopulation NFE AF= 0.00721 (490/67990). AF 95% confidence interval is 0.00668. There are 4 homozygotes in gnomad4. There are 244 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
BS2
High Homozygotes in GnomAd4 at 4 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
TTNNM_001267550.2 linkuse as main transcriptc.72132T>C p.Gly24044= synonymous_variant 326/363 ENST00000589042.5 NP_001254479.2
TTN-AS1NR_038272.1 linkuse as main transcriptn.2044-8572A>G intron_variant, non_coding_transcript_variant

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkuse as main transcriptc.72132T>C p.Gly24044= synonymous_variant 326/3635 NM_001267550.2 ENSP00000467141 P1
TTN-AS1ENST00000659121.1 linkuse as main transcriptn.417-23596A>G intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes
AF:
0.00387
AC:
589
AN:
152058
Hom.:
4
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00109
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00190
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00160
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00721
Gnomad OTH
AF:
0.00383
GnomAD3 exomes
AF:
0.00365
AC:
906
AN:
248202
Hom.:
6
AF XY:
0.00368
AC XY:
496
AN XY:
134694
show subpopulations
Gnomad AFR exome
AF:
0.000582
Gnomad AMR exome
AF:
0.00180
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.000883
Gnomad FIN exome
AF:
0.00158
Gnomad NFE exome
AF:
0.00670
Gnomad OTH exome
AF:
0.00366
GnomAD4 exome
AF:
0.00600
AC:
8765
AN:
1461164
Hom.:
40
Cov.:
38
AF XY:
0.00588
AC XY:
4271
AN XY:
726868
show subpopulations
Gnomad4 AFR exome
AF:
0.000956
Gnomad4 AMR exome
AF:
0.00224
Gnomad4 ASJ exome
AF:
0.000115
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.000939
Gnomad4 FIN exome
AF:
0.00232
Gnomad4 NFE exome
AF:
0.00730
Gnomad4 OTH exome
AF:
0.00522
GnomAD4 genome
AF:
0.00386
AC:
588
AN:
152176
Hom.:
4
Cov.:
32
AF XY:
0.00328
AC XY:
244
AN XY:
74378
show subpopulations
Gnomad4 AFR
AF:
0.00108
Gnomad4 AMR
AF:
0.00183
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00160
Gnomad4 NFE
AF:
0.00721
Gnomad4 OTH
AF:
0.00379
Alfa
AF:
0.00528
Hom.:
0
Bravo
AF:
0.00383
Asia WGS
AF:
0.000866
AC:
3
AN:
3478
EpiCase
AF:
0.00595
EpiControl
AF:
0.00629

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:3Benign:15
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not specified Benign:6
Benign, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineMar 06, 2012Gly21476Gly in exon 275 of TTN: This variant is not expected to have clinical si gnificance because it does not alter an amino acid residue and has been identifi ed in 0.7% (46/6632) of European American chromosomes from a broad population by the NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS; dbSNP rs5 6169243). -
Benign, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Jul 14, 2015- -
Benign, criteria provided, single submitterclinical testingGeneDxMar 25, 2013This 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 testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpNov 29, 2021- -
Likely benign, criteria provided, single submitterclinical testingGenetic Services Laboratory, University of ChicagoFeb 08, 2017- -
Benign, criteria provided, single submitterclinical testingAthena DiagnosticsMar 04, 2020- -
not provided Benign:2
Likely benign, criteria provided, single submitterclinical testingARUP Laboratories, Molecular Genetics and Genomics, ARUP LaboratoriesNov 29, 2023- -
Likely benign, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenAug 01, 2024TTN: BP4, BP7, BS2 -
Tip-toe gait Pathogenic:1
Likely pathogenic, no assertion criteria providedclinical testingPractice for Gait Abnormalities, David Pomarino, Competency Network Toe Walking c/o Practice PomarinoNov 27, 2020Myopathy refers to diseases that affect skeletal Muscles. These diseases attack muscle fibers, making muscles weak. Inherited myopathies are often caused by inheriting an abnormal gene mutation from a parent that causes the disease. Symptoms of congenital myopathies usually start at birth or in early childhood, but may not appear until the teen years or even later in adulthood. Congenital myopathies are somewhat unique compared with other inherited myopathies, as weakness typically affects all muscles and is often not progressive. Symptoms are: Muscle weakness, most commonly of upper arms and shoulders and thighs, muscle cramps, stiffness and spasms, fatigue with exertion and lack of energy. Our patients all walk on tiptoe, so they show similar symptoms. When we genetically test them with our toe walking panel, we find that around 90 per cent of them have a genetic variant that explains their toe walking. These can be assigned, for example, to the area of myopathies (such as variants of the COL6A3 gene), the area of hereditary neuropathies (such as variants of the KMT2C gene) or the area of metabolic diseases (such as variants of the PYGM gene). In a smaller group of patients with almost identical symptoms, no abnormality is found in the genes of our panel, but spastic paraplegia can be detected. In another small group of our toe walkers, no abnormalities can be detected in the genes analysed in our toe walking panel, nor do they suffer from spastic paraplegia, as is also the case with healthy children. In contrast to these, however, they show a tiptoe gait. These patients suffer from infantile cerebral palsy, in which toe walking can also be observed. -
Autosomal recessive limb-girdle muscular dystrophy type 2J Uncertain:1
Uncertain significance, 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, 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. -
Dilated cardiomyopathy 1G Uncertain:1
Uncertain significance, 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, 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
Uncertain significance, 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, 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. -
TTN-related disorder Benign:1
Likely benign, no assertion criteria providedclinical testingPreventionGenetics, part of Exact SciencesMay 30, 2019This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
Benign, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJan 31, 2024- -
Cardiomyopathy Benign:1
Benign, criteria provided, single submitterclinical testingCHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern OntarioNov 02, 2017- -
Tibial muscular dystrophy Benign:1
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:1
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. -
Cardiovascular phenotype Benign:1
Likely benign, criteria provided, single submitterclinical testingAmbry GeneticsMar 18, 2013This 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. -
TTN-related myopathy Benign:1
Likely benign, criteria provided, single submitterclinical testingMolecular Genetics, Royal Melbourne HospitalJun 06, 2023- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.49
CADD
Benign
0.036
DANN
Benign
0.67

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: rs56169243; hg19: chr2-179438727; API