2-178664730-T-G

Position:

chr2-178664730-T-G

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_001267550.2(TTN):c.36126A>C(p.Glu12042Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00102 in 1,612,392 control chromosomes in the GnomAD database, including 22 homozygotes. In-silico tool predicts a benign outcome for this variant. 9/13 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0056 ( 7 hom., cov: 32)

Exomes 𝑓: 0.00055 ( 15 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:12

Conservation

PhyloP100: -0.697

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 links:

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]

TTN-AS1 links:

LOC124906100 (HGNC:):

LOC124906100 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -20 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.0035236776).

BP6

Variant 2-178664730-T-G is Benign according to our data. Variant chr2-178664730-T-G is described in ClinVar as [Likely_benign]. Clinvar id is 238751.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178664730-T-G is described in Lovd as [Benign]. Variant chr2-178664730-T-G is described in Lovd as [Likely_benign].

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.0056 (852/152264) while in subpopulation AFR AF= 0.0197 (817/41554). AF 95% confidence interval is 0.0185. There are 7 homozygotes in gnomad4. There are 385 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

BS2

High Homozygotes in GnomAd4 at 7 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.36126A>C	p.Glu12042Asp	missense_variant	167/363	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 link	c.36126A>C	p.Glu12042Asp	missense_variant	167/363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.00554

AC:

843

AN:

152146

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0195

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00144

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00478

GnomAD3 exomes

AF:

0.00143

AC:

343

AN:

240628

Hom.:

AF XY:

0.000999

AC XY:

132

AN XY:

132158

show subpopulations

Gnomad AFR exome

AF:

0.0217

Gnomad AMR exome

AF:

0.000730

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.000132

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000281

Gnomad OTH exome

AF:

0.000338

GnomAD4 exome

AF:

0.000547

AC:

798

AN:

1460128

Hom.:

Cov.:

AF XY:

0.000482

AC XY:

350

AN XY:

726364

show subpopulations

Gnomad4 AFR exome

AF:

0.0189

Gnomad4 AMR exome

AF:

0.000717

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000153

Gnomad4 OTH exome

AF:

0.00174

GnomAD4 genome

AF:

0.00560

AC:

852

AN:

152264

Hom.:

Cov.:

AF XY:

0.00517

AC XY:

385

AN XY:

74460

show subpopulations

Gnomad4 AFR

AF:

0.0197

Gnomad4 AMR

AF:

0.00144

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00473

Alfa

AF:

0.00262

Hom.:

Bravo

AF:

0.00616

ESP6500AA

AF:

0.0223

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.00176

AC:

203

Asia WGS

AF:

0.00375

AC:

AN:

3478

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:12

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:3

Benign, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -
Benign, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -

not provided

Benign:3

Likely benign, no assertion criteria provided	clinical testing	Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)	-	- -
Likely benign, criteria provided, single submitter	not provided	Breakthrough Genomics, Breakthrough Genomics	-	- -
Likely benign, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Sep 21, 2023	- -

TTN-related disorder

Benign:1

Benign, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

May 22, 2019

This variant is classified as 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

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G

Benign:1

Benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 31, 2024

- -

Early-onset myopathy with fatal cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Tibial muscular dystrophy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Myopathy, myofibrillar, 9, with early respiratory failure

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Benign

-0.53

BayesDel_noAF

Benign

-0.51

CADD

Benign

DANN

Uncertain

0.98

Eigen

Benign

-0.65

Eigen_PC

Benign

-0.76

FATHMM_MKL

Benign

0.10

LIST_S2

Benign

0.39

MetaRNN

Benign

0.0035

MetaSVM

Benign

-1.0

Vest4

0.075

MVP

0.54

MPC

0.077

ClinPred

0.00083

GERP RS

0.76

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over