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GeneBe

rs539735520

Variant summary

Our verdict is Benign. Variant got -19 ACMG points: 1P and 20B. PP2BP4_StrongBP6_Very_StrongBS1BS2

The NM_001267550.2(TTN):c.104347C>T(p.Leu34783Phe) variant causes a missense change. The variant allele was found at a frequency of 0.000452 in 1,613,850 control chromosomes in the GnomAD database, including 13 homozygotes. In-silico tool predicts a benign outcome for this variant. 12/18 in silico tools predict 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. L34783L) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00014 ( 1 hom., cov: 32)
Exomes 𝑓: 0.00048 ( 12 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

6
10

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:15

Conservation

PhyloP100: 5.22
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 -19 ACMG points.

PP2
Missense variant where missense usually causes diseases, TTN
BP4
Computational evidence support a benign effect (MetaRNN=0.0074152946).
BP6
Variant 2-178532268-G-A is Benign according to our data. Variant chr2-178532268-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 282653.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178532268-G-A is described in Lovd as [Likely_benign]. Variant chr2-178532268-G-A is described in Lovd as [Benign].
BS1
Variant frequency is greater than expected in population sas. gnomad4_exome allele frequency = 0.000484 (707/1461570) while in subpopulation SAS AF= 0.00796 (687/86258). AF 95% confidence interval is 0.00747. There are 12 homozygotes in gnomad4_exome. There are 546 alleles in male gnomad4_exome subpopulation. Median coverage is 40. This position pass quality control queck.
BS2
High Homozygotes in GnomAdExome at 4 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
TTNNM_001267550.2 linkuse as main transcriptc.104347C>T p.Leu34783Phe missense_variant 358/363 ENST00000589042.5
TTN-AS1NR_038272.1 linkuse as main transcriptn.220-3464G>A intron_variant, non_coding_transcript_variant

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
TTNENST00000589042.5 linkuse as main transcriptc.104347C>T p.Leu34783Phe missense_variant 358/3635 NM_001267550.2 P1
TTN-AS1ENST00000659121.1 linkuse as main transcriptn.416+8632G>A intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes
AF:
0.000145
AC:
22
AN:
152162
Hom.:
1
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00435
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00104
AC:
259
AN:
248298
Hom.:
4
AF XY:
0.00151
AC XY:
204
AN XY:
134670
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00843
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.000166
GnomAD4 exome
AF:
0.000484
AC:
707
AN:
1461570
Hom.:
12
Cov.:
40
AF XY:
0.000751
AC XY:
546
AN XY:
727078
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00796
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
8.99e-7
Gnomad4 OTH exome
AF:
0.000315
GnomAD4 genome
AF:
0.000144
AC:
22
AN:
152280
Hom.:
1
Cov.:
32
AF XY:
0.000269
AC XY:
20
AN XY:
74462
show subpopulations
Gnomad4 AFR
AF:
0.0000241
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00435
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000492
Hom.:
0
Bravo
AF:
0.0000151
ExAC
AF:
0.00110
AC:
133
Asia WGS
AF:
0.00202
AC:
7
AN:
3478

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:15
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:3
Benign, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Aug 18, 2015- -
Benign, no assertion criteria providedclinical testingClinical Genetics, Academic Medical Center-- -
Benign, no assertion criteria providedclinical testingClinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center-- -
not provided Benign:3
Likely benign, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenMar 01, 2023TTN: BP4, BS2 -
Benign, criteria provided, single submitterclinical testingGeneDxJul 13, 2018- -
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:1
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 04, 2024- -
Cardiomyopathy Benign:1
Benign, criteria provided, single submitterclinical testingCHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern OntarioMar 23, 2018- -
Early-onset myopathy with fatal cardiomyopathy Benign:1
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Myopathy, myofibrillar, 9, with early respiratory failure Benign:1
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
TTN-related condition Benign:1
Benign, criteria provided, single submitterclinical testingPreventionGenetics, part of Exact SciencesJul 10, 2019This variant is classified as benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -
Tibial muscular dystrophy Benign:1
Benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 10, 2021- -
Primary dilated cardiomyopathy Benign:1
Likely benign, criteria provided, single submitterresearchGenetics and Genomics Program, Sidra Medicine-- -
Hypertrophic cardiomyopathy Benign:1
Likely benign, criteria provided, single submitterresearchGenetics and Genomics Program, Sidra Medicine-- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.24
BayesDel_addAF
Benign
-0.40
T
BayesDel_noAF
Benign
-0.34
Cadd
Benign
19
Dann
Benign
0.96
Eigen
Uncertain
0.31
Eigen_PC
Uncertain
0.38
FATHMM_MKL
Uncertain
0.90
D
LIST_S2
Uncertain
0.90
D;D;D;.;D;D;D
M_CAP
Benign
0.029
D
MetaRNN
Benign
0.0074
T;T;T;T;T;T;T
MetaSVM
Benign
-0.68
T
MutationTaster
Benign
1.0
D;D;D;D;D;D
PrimateAI
Benign
0.48
T
PROVEAN
Uncertain
-2.5
N;N;.;.;N;N;.
REVEL
Benign
0.15
Sift
Uncertain
0.0080
D;D;.;.;D;D;.
Polyphen
0.93
.;.;.;P;.;.;P
Vest4
0.34
MutPred
0.16
.;.;.;Gain of catalytic residue at L33142 (P = 0.0422);.;.;Gain of catalytic residue at L33142 (P = 0.0422);
MVP
0.71
MPC
0.23
ClinPred
0.088
T
GERP RS
5.6

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: rs539735520; hg19: chr2-179396995; API