2-178605274-C-T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_001267550.2(TTN):c.53903G>A(p.Arg17968His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000111 in 1,591,464 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R17968P) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000092 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00011 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:7B:1

Conservation

PhyloP100: 3.46

Publications

2 publications found

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:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.15629423).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001267550.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
TTN	NM_001267550.2	MANE Select	c.53903G>A	p.Arg17968His	missense	Exon 280 of 363	NP_001254479.2	Q8WZ42-12
TTN	NM_001256850.1		c.48980G>A	p.Arg16327His	missense	Exon 230 of 313	NP_001243779.1	Q8WZ42-1
TTN	NM_133378.4		c.46199G>A	p.Arg15400His	missense	Exon 229 of 312	NP_596869.4	Q8WZ42-11

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
TTN	ENST00000589042.5	TSL:5 MANE Select	c.53903G>A	p.Arg17968His	missense	Exon 280 of 363	ENSP00000467141.1	Q8WZ42-12
TTN	ENST00000446966.2	TSL:1	c.53747G>A	p.Arg17916His	missense	Exon 278 of 361	ENSP00000408004.2	A0A1B0GXE3
TTN	ENST00000436599.2	TSL:1	c.53627G>A	p.Arg17876His	missense	Exon 278 of 361	ENSP00000405517.2	A0A0C4DG59

Frequencies

GnomAD3 genomes

AF:

0.0000922

AC:

AN:

151786

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000193

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000883

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000876

AC:

AN:

228238

AF XY:

0.000121

show subpopulations

Gnomad AFR exome

AF:

0.000273

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000500

Gnomad NFE exome

AF:

0.000143

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000113

AC:

162

AN:

1439678

Hom.:

Cov.:

AF XY:

0.000119

AC XY:

AN XY:

714134

show subpopulations

African (AFR)

AF:

0.000153

AC:

AN:

32612

American (AMR)

AF:

0.00

AC:

AN:

41920

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25034

East Asian (EAS)

AF:

0.000102

AC:

AN:

39138

South Asian (SAS)

AF:

0.00

AC:

AN:

82702

European-Finnish (FIN)

AF:

0.0000386

AC:

AN:

51870

Middle Eastern (MID)

AF:

0.000530

AC:

AN:

5664

European-Non Finnish (NFE)

AF:

0.000133

AC:

146

AN:

1101366

Other (OTH)

AF:

0.0000337

AC:

AN:

59372

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.464

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000922

AC:

AN:

151786

Hom.:

Cov.:

AF XY:

0.0000945

AC XY:

AN XY:

74086

show subpopulations

African (AFR)

AF:

0.000193

AC:

AN:

41348

American (AMR)

AF:

0.00

AC:

AN:

15224

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5126

South Asian (SAS)

AF:

0.00

AC:

AN:

4802

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10590

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000883

AC:

AN:

67912

Other (OTH)

AF:

0.00

AC:

AN:

2088

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.493

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000726

Hom.:

Bravo

AF:

0.000136

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.000265

AC:

ESP6500EA

AF:

0.000366

AC:

ExAC

AF:

0.0000913

AC:

ClinVar

ClinVar submissions

Significance:Conflicting classifications of pathogenicity

Revision:criteria provided, conflicting classifications

View on ClinVar

Pathogenic

VUS

Benign

Condition

not provided (2)

not specified (2)

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1838244:Tibial muscular dystrophy;C1858763:Dilated cardiomyopathy 1G;C1861065:Hypertrophic cardiomyopathy 9;C1863599:Myopathy, myofibrillar, 9, with early respiratory failure;C2673677:Early-onset myopathy with fatal cardiomyopathy (1)

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

Cardiomyopathy (1)

Cardiovascular phenotype (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.11

BayesDel_addAF

Benign

-0.25

BayesDel_noAF

Benign

-0.30

CADD

Benign

(source)

DANN

Benign

0.89

Eigen

Uncertain

0.52

Eigen_PC

Uncertain

0.57

FATHMM_MKL

Uncertain

0.90

LIST_S2

Benign

0.85

M_CAP

Benign

0.054

MetaRNN

Benign

0.16

MetaSVM

Benign

-0.39

MutationAssessor

Benign

1.4

PhyloP100

3.5

PrimateAI

Uncertain

0.55

PROVEAN

Uncertain

-2.9

REVEL

Benign

0.29

Sift

Benign

0.22

Polyphen

1.0

Vest4

0.38

MVP

0.36

MPC

0.45

ClinPred

0.13

GERP RS

5.7

Mutation Taster

=84/16

polymorphism

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over