chr2-178689822-G-C

Position:

chr2-178689822-G-C

Variant summary

Our verdict is Benign. Variant got -10 ACMG points: 1P and 11B. PP2BP4_ModerateBP6BS1BS2

The NM_001267550.2(TTN):c.31837C>G(p.Pro10613Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000395 in 1,611,062 control chromosomes in the GnomAD database, including 5 homozygotes. In-silico tool predicts a benign outcome for this variant. 11/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00033 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00040 ( 5 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:8B:6

Conservation

PhyloP100: 3.02

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:

LOC124907912 (HGNC:):

LOC124907912 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:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -10 ACMG points.

PP2

Missense variant in gene, where missense usually causes diseases (based on misZ statistic), TTN. . Gene score misZ -1.1021 (greater than the threshold 3.09). Trascript score misZ 6.9794 (greater than threshold 3.09). GenCC has associacion of gene with dilated cardiomyopathy, tibial muscular dystrophy, early-onset myopathy with fatal cardiomyopathy, autosomal recessive centronuclear myopathy, hypertrophic cardiomyopathy, hypertrophic cardiomyopathy 9, TTN-related myopathy, dilated cardiomyopathy 1G, arrhythmogenic right ventricular cardiomyopathy, myopathy, myofibrillar, 9, with early respiratory failure, familial isolated dilated cardiomyopathy, childhood-onset progressive contractures-limb-girdle weakness-muscle dystrophy syndrome, autosomal recessive limb-girdle muscular dystrophy type 2J.

BP4

Computational evidence support a benign effect (MetaRNN=0.07983962).

BP6

Variant 2-178689822-G-C is Benign according to our data. Variant chr2-178689822-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 46858.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=4, Benign=2, Uncertain_significance=8}. Variant chr2-178689822-G-C is described in Lovd as [Likely_benign].

BS1

Variant frequency is greater than expected in population mid. gnomad4_exome allele frequency = 0.000401 (585/1458806) while in subpopulation MID AF= 0.0151 (87/5750). AF 95% confidence interval is 0.0126. There are 5 homozygotes in gnomad4_exome. There are 270 alleles in male gnomad4_exome subpopulation. Median coverage is 31. This position pass quality control queck.

BS2

High Homozygotes in GnomAdExome4 at 5 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein
TTN	NM_001267550.2 linkuse as main transcript	c.31837C>G	p.Pro10613Ala	missense_variant	122/363	ENST00000589042.5	NP_001254479.2
LOC124907912	XR_007087321.1 linkuse as main transcript	n.1685G>C		non_coding_transcript_exon_variant	1/2
LOC124906100	XR_007087318.1 linkuse as main transcript	n.2186-23932G>C		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.31837C>G	p.Pro10613Ala	missense_variant	122/363	5	NM_001267550.2	ENSP00000467141	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.503-44682G>C		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.000342

AC:

AN:

152138

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00131

Gnomad ASJ

AF:

0.000865

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.000309

Gnomad OTH

AF:

0.00287

GnomAD3 exomes

AF:

0.000372

AC:

AN:

247188

Hom.:

AF XY:

0.000388

AC XY:

AN XY:

134086

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000762

Gnomad ASJ exome

AF:

0.000602

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.000268

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000382

Gnomad OTH exome

AF:

0.00150

GnomAD4 exome

AF:

0.000401

AC:

585

AN:

1458806

Hom.:

Cov.:

AF XY:

0.000372

AC XY:

270

AN XY:

725622

show subpopulations

Gnomad4 AFR exome

AF:

0.000271

Gnomad4 AMR exome

AF:

0.000814

Gnomad4 ASJ exome

AF:

0.000615

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000199

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000338

Gnomad4 OTH exome

AF:

0.000747

GnomAD4 genome

AF:

0.000335

AC:

AN:

152256

Hom.:

Cov.:

AF XY:

0.000403

AC XY:

AN XY:

74452

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00131

Gnomad4 ASJ

AF:

0.000865

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000309

Gnomad4 OTH

AF:

0.00237

Alfa

AF:

0.000447

Hom.:

Bravo

AF:

0.000552

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.00

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000122

AC:

ExAC

AF:

0.000339

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.000874

EpiControl

AF:

0.000771

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:8Benign:6

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1Benign:3

Likely benign, criteria provided, single submitter	clinical testing	Athena Diagnostics	Oct 23, 2018	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Aug 24, 2015	- -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Mar 02, 2021	This variant is associated with the following publications: (PMID: 24503780) -
Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jul 01, 2024	TTN: BP4 -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Baylor Genetics	Jan 08, 2020	This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -
Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Apr 27, 2017	This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

not specified

Uncertain:1Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Jul 24, 2012	The Pro9369Ala variant in TTN has not been reported in the literature nor previo usly identified by our laboratory. This variant has been identified in 1/8176 Eu ropean American chromosomes from a broad population by the NHLBI Exome Sequencin g Project (http://evs.gs.washington.edu/EVS/), though this could represent a pre symptomatic individual. Computational analyses (biochemical amino acid propertie s, conservation, AlignGVGD, PolyPhen2, and SIFT) do not argue for or against an impact to the protein. Additional information is needed to fully assess the clin ical significance of the Pro9369Ala variant. -
Likely benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Dec 11, 2023	Variant summary: TTN c.28105C>G (p.Pro9369Ala) results in a non-conservative amino acid change located in the I-band region of the encoded protein sequence. Two of four in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00037 in 247188 control chromosomes, predominantly at a frequency of 0.00076 within the Latino subpopulation in the gnomAD database. The observed variant frequency within Latino control individuals in the gnomAD database is approximately 2 fold of the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Dilated Cardiomyopathy phenotype (0.00039), strongly suggesting that the variant is a benign polymorphism found primarily in populations of Latino origin. c.28105C>G has been reported in the literature in an individual affected with Dilated Cardiomyopathy and an individual reported with Sudden Unexplained Death (Pugh_2014, Campuzano_2015). These reports do not provide unequivocal conclusions about association of the variant with Dilated Cardiomyopathy. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 24503780, 26516846).Nine submitters have cited clinical-significance assessments for this variant to ClinVar after 2014 and classified as benign/likely benign (n=4) and VUS (n=5). Based on the evidence outlined above, the variant was classified as likely benign. -

TTN-related disorder

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Mar 13, 2023

The TTN c.28105C>G variant is predicted to result in the amino acid substitution p.Pro9369Ala. This variant has been reported in an individual with dilated cardiomyopathy and interpreted as uncertain significance (Table S3, referred to as g.179554549G>C/NM_133378.4:c.28105C>G, Pugh et al. 2014. PubMed ID: 24503780). This variant is reported in 0.077% of alleles in individuals of Latino descent in gnomAD (http://gnomad.broadinstitute.org/variant/2-179554549-G-C). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

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

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 27, 2017

- -

Dilated cardiomyopathy 1G

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Early-onset myopathy with fatal cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Tibial muscular dystrophy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -

Myopathy, myofibrillar, 9, with early respiratory failure

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.069

BayesDel_addAF

Benign

-0.26

BayesDel_noAF

Benign

-0.24

CADD

Benign

DANN

Uncertain

0.98

DEOGEN2

Benign

0.082

.;.;.;.;T

Eigen

Uncertain

0.35

Eigen_PC

Uncertain

0.39

FATHMM_MKL

Uncertain

0.97

LIST_S2

Benign

0.80

T;T;.;T;T

M_CAP

Benign

0.054

MetaRNN

Benign

0.080

T;T;T;T;T

MetaSVM

Uncertain

-0.21

MutationTaster

Benign

0.70

D;D;D;D;N;N

PrimateAI

Benign

0.39

PROVEAN

Uncertain

-4.0

D;.;.;.;D

REVEL

Uncertain

0.30

Sift

Pathogenic

0.0

D;.;.;.;D

Polyphen

0.47

.;.;P;P;.

Vest4

0.33

MVP

0.41

MPC

0.20

ClinPred

0.12

GERP RS

4.6

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.

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