NM_133379.5:c.12653T>C

Variant names:

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_ModerateBS1_SupportingBS2

The NM_133379.5(TTN):c.12653T>C(p.Ile4218Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000124 in 1,612,912 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I4218M) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000072 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00013 ( 2 hom. )

Consequence

TTN
NM_133379.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 8.50

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: Benign. The variant received -7 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.13061449).

BS1

Variant frequency is greater than expected in population sas. GnomAdExome4 allele frequency = 0.000129 (189/1460816) while in subpopulation SAS AF = 0.00203 (175/86216). AF 95% confidence interval is 0.00178. There are 2 homozygotes in GnomAdExome4. There are 126 alleles in the male GnomAdExome4 subpopulation. Median coverage is 36. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

BS2

High Homozygotes in GnomAdExome4 at 2 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_133379.5 link	c.12653T>C	p.Ile4218Thr	missense_variant	Exon 46 of 46	ENST00000360870.10	NP_596870.2	Q8WZ42-6Q7Z3B7
TTN	NM_001267550.2 link	c.11311+3377T>C		intron_variant	Intron 47 of 362	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000360870.10 link	c.12653T>C	p.Ile4218Thr	missense_variant	Exon 46 of 46	5	NM_133379.5	ENSP00000354117.4		Q8WZ42-6
TTN	ENST00000589042.5 link	c.11311+3377T>C		intron_variant	Intron 47 of 362	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.0000724

AC:

AN:

151978

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00186

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000277

AC:

AN:

248912

AF XY:

0.000363

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 FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.000166

GnomAD4 exome

AF:

0.000129

AC:

189

AN:

1460816

Hom.:

Cov.:

AF XY:

0.000173

AC XY:

126

AN XY:

726706

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33430

American (AMR)

AF:

0.00

AC:

AN:

44610

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26088

East Asian (EAS)

AF:

0.00

AC:

AN:

39612

South Asian (SAS)

AF:

0.00203

AC:

175

AN:

86216

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53362

Middle Eastern (MID)

AF:

0.000347

AC:

AN:

5756

European-Non Finnish (NFE)

AF:

9.00e-7

AC:

AN:

1111398

Other (OTH)

AF:

0.000166

AC:

AN:

60344

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.504

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

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:

0.0000723

AC:

AN:

152096

Hom.:

Cov.:

AF XY:

0.0000807

AC XY:

AN XY:

74344

show subpopulations

African (AFR)

AF:

0.0000481

AC:

AN:

41546

American (AMR)

AF:

0.00

AC:

AN:

15256

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5168

South Asian (SAS)

AF:

0.00187

AC:

AN:

4822

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10616

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67902

Other (OTH)

AF:

0.00

AC:

AN:

2110

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.561

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:

0.0000551

Hom.:

Bravo

AF:

0.0000416

ExAC

AF:

0.000322

AC:

Asia WGS

AF:

0.000866

AC:

AN:

3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Sep 12, 2012

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The Ile4218Thr variant in TTN has not been reported in the literature nor previo usly identified by our laboratory. Computational analyses are limited or unavail able for this variant. Additional information is needed to fully assess the clin ical significance of the Ile4218Thr variant. -

not provided

Uncertain:1

May 11, 2017

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Benign

-0.21

BayesDel_noAF

Uncertain

-0.080

CADD

Benign

(source)

DANN

Uncertain

0.99

Eigen

Uncertain

0.62

Eigen_PC

Uncertain

0.49

FATHMM_MKL

Pathogenic

1.0

LIST_S2

Benign

0.48

M_CAP

Benign

0.063

MetaRNN

Benign

0.13

MetaSVM

Uncertain

0.65

PhyloP100

8.5

PROVEAN

Uncertain

-2.8

REVEL

Pathogenic

0.68

Sift

Uncertain

0.0010

Sift4G

Uncertain

0.040

Polyphen

0.93

Vest4

0.77

MVP

0.77

ClinPred

0.23

GERP RS

5.8

Mutation Taster

=75/25

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over