2-178725625-A-G

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.20579T>C(p.Leu6860Pro) variant causes a missense change. The variant allele was found at a frequency of 0.00000817 in 1,591,538 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 Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000083 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 7.15

Publications

0 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:

ENSG00000267784 (HGNC:):

ENSG00000267784 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=0.2560935).

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.20579T>C	p.Leu6860Pro	missense	Exon 71 of 363	NP_001254479.2
TTN	NM_001256850.1		c.19628T>C	p.Leu6543Pro	missense	Exon 69 of 313	NP_001243779.1
TTN	NM_133378.4		c.16847T>C	p.Leu5616Pro	missense	Exon 68 of 312	NP_596869.4

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
TTN	ENST00000589042.5	TSL:5 MANE Select	c.20579T>C	p.Leu6860Pro	missense	Exon 71 of 363	ENSP00000467141.1
TTN	ENST00000446966.2	TSL:1	c.20579T>C	p.Leu6860Pro	missense	Exon 71 of 361	ENSP00000408004.2
TTN	ENST00000436599.2	TSL:1	c.20303T>C	p.Leu6768Pro	missense	Exon 69 of 361	ENSP00000405517.2

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152148

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:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000217

AC:

AN:

230330

AF XY:

0.0000161

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:

0.0000474

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000834

AC:

AN:

1439390

Hom.:

Cov.:

AF XY:

0.00000701

AC XY:

AN XY:

713666

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

32596

American (AMR)

AF:

0.00

AC:

AN:

42134

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

24922

East Asian (EAS)

AF:

0.00

AC:

AN:

39424

South Asian (SAS)

AF:

0.00

AC:

AN:

82516

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5648

European-Non Finnish (NFE)

AF:

0.0000109

AC:

AN:

1100172

Other (OTH)

AF:

0.00

AC:

AN:

59354

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.496

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:

0.00000657

AC:

AN:

152148

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74316

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41458

American (AMR)

AF:

0.00

AC:

AN:

15264

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5188

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10618

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68004

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.625

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000331

Hom.:

Bravo

AF:

0.0000151

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:1

May 30, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: TTN c.16847T>C (p.Leu5616Pro) 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 damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.2e-05 in 230330 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.16847T>C in individuals affected with Limb-Girdle Muscular Dystrophy, Type 2J and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 535368). Based on the evidence outlined above, the variant was classified as uncertain significance.

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

Uncertain:1

Sep 14, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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

Uncertain:1

Aug 23, 2021

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.32

BayesDel_addAF

Benign

-0.13

BayesDel_noAF

Benign

-0.32

CADD

Benign

(source)

DANN

Benign

0.96

Eigen

Benign

0.11

Eigen_PC

Uncertain

0.31

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Benign

0.67

M_CAP

Benign

0.029

MetaRNN

Benign

0.26

MetaSVM

Benign

-1.0

PhyloP100

7.2

PrimateAI

Uncertain

0.71

PROVEAN

Uncertain

-4.3

REVEL

Uncertain

0.33

Sift

Benign

0.13

Polyphen

0.0090

Vest4

0.53

MVP

0.44

MPC

0.14

ClinPred

0.22

GERP RS

5.9

Mutation Taster

=61/39

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

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over