2-178777862-C-T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6

The NM_001267550.2(TTN):c.4322G>A(p.Arg1441His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000576 in 1,614,034 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. R1441C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000060 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6B:2

Conservation

PhyloP100: 7.67

Publications

23 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:

LOC101927055 (HGNC:):

LOC101927055 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.15384397).

BP6

Variant 2-178777862-C-T is Benign according to our data. Variant chr2-178777862-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 332957.

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
TTN	NM_001267550.2	MANE Select	c.4322G>A	p.Arg1441His	missense	Exon 25 of 363	NP_001254479.2
TTN	NM_001256850.1		c.4322G>A	p.Arg1441His	missense	Exon 25 of 313	NP_001243779.1
TTN	NM_133378.4		c.4322G>A	p.Arg1441His	missense	Exon 25 of 312	NP_596869.4

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
TTN	ENST00000589042.5	TSL:5 MANE Select	c.4322G>A	p.Arg1441His	missense	Exon 25 of 363	ENSP00000467141.1
TTN	ENST00000446966.2	TSL:1	c.4322G>A	p.Arg1441His	missense	Exon 25 of 361	ENSP00000408004.2
TTN	ENST00000436599.2	TSL:1	c.4046G>A	p.Arg1349His	missense	Exon 23 of 361	ENSP00000405517.2

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152182

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000385

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.000478

GnomAD2 exomes

AF:

0.0000399

AC:

AN:

250888

AF XY:

0.0000443

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000530

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000595

AC:

AN:

1461734

Hom.:

Cov.:

AF XY:

0.0000674

AC XY:

AN XY:

727170

show subpopulations

African (AFR)

AF:

0.0000598

AC:

AN:

33464

American (AMR)

AF:

0.0000447

AC:

AN:

44716

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26130

East Asian (EAS)

AF:

0.000832

AC:

AN:

39684

South Asian (SAS)

AF:

0.0000232

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53414

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.0000423

AC:

AN:

1111918

Other (OTH)

AF:

0.0000166

AC:

AN:

60384

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.491

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:

0.0000394

AC:

AN:

152300

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74480

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41568

American (AMR)

AF:

0.00

AC:

AN:

15294

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.000386

AC:

AN:

5180

South Asian (SAS)

AF:

0.000207

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68020

Other (OTH)

AF:

0.000473

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.542

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:

0.00

Hom.:

Bravo

AF:

0.0000113

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

ClinVar submissions as Germline

Significance:Conflicting classifications of pathogenicity

Revision:criteria provided, conflicting classifications

View on ClinVar

Pathogenic

VUS

Benign

Condition

Autosomal recessive limb-girdle muscular dystrophy type 2J (1)

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

Dilated cardiomyopathy 1G (1)

Early-onset myopathy with fatal cardiomyopathy (1)

Myopathy, myofibrillar, 9, with early respiratory failure (1)

not provided (1)

not specified (1)

Tibial muscular dystrophy (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.38

BayesDel_addAF

Benign

-0.021

BayesDel_noAF

Uncertain

-0.030

CADD

Uncertain

(source)

DANN

Uncertain

0.99

Eigen

Pathogenic

0.84

Eigen_PC

Pathogenic

0.83

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.96

M_CAP

Benign

0.033

MetaRNN

Benign

0.15

MetaSVM

Uncertain

-0.14

PhyloP100

7.7

PrimateAI

Uncertain

0.73

PROVEAN

Uncertain

-3.2

REVEL

Uncertain

0.38

Sift

Benign

0.030

Sift4G

Uncertain

0.0030

Polyphen

1.0

Vest4

0.22

MutPred

0.30

Loss of MoRF binding (P = 0.0449)

MVP

0.39

MPC

0.51

ClinPred

0.49

GERP RS

5.5

Mutation Taster

=93/7

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