chr2-178615400-T-G

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.

The NM_001267550.2(TTN):c.48545A>C(p.Asp16182Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000013 in 1,612,546 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 7.97

Publications

3 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: Uncertain_significance. The variant received 0 ACMG points.

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.48545A>C	p.Asp16182Ala	missense	Exon 259 of 363	NP_001254479.2
TTN	NM_001256850.1		c.43622A>C	p.Asp14541Ala	missense	Exon 209 of 313	NP_001243779.1
TTN	NM_133378.4		c.40841A>C	p.Asp13614Ala	missense	Exon 208 of 312	NP_596869.4

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
TTN	ENST00000589042.5	TSL:5 MANE Select	c.48545A>C	p.Asp16182Ala	missense	Exon 259 of 363	ENSP00000467141.1
TTN	ENST00000446966.2	TSL:1	c.48389A>C	p.Asp16130Ala	missense	Exon 257 of 361	ENSP00000408004.2
TTN	ENST00000436599.2	TSL:1	c.48269A>C	p.Asp16090Ala	missense	Exon 257 of 361	ENSP00000405517.2

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

151924

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000242

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000201

AC:

AN:

248394

AF XY:

0.0000148

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000290

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000356

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000137

AC:

AN:

1460622

Hom.:

Cov.:

AF XY:

0.0000124

AC XY:

AN XY:

726604

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33388

American (AMR)

AF:

0.00

AC:

AN:

44694

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26088

East Asian (EAS)

AF:

0.00

AC:

AN:

39638

South Asian (SAS)

AF:

0.00

AC:

AN:

86204

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53400

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5750

European-Non Finnish (NFE)

AF:

0.0000162

AC:

AN:

1111158

Other (OTH)

AF:

0.0000332

AC:

AN:

60302

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.487

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:

0.00000658

AC:

AN:

151924

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74190

show subpopulations

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.0000242

AC:

AN:

41404

American (AMR)

AF:

0.00

AC:

AN:

15248

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5132

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10616

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67912

Other (OTH)

AF:

0.00

AC:

AN:

2092

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.325

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000988

Hom.:

Bravo

AF:

0.0000113

ExAC

AF:

0.00000827

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

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

Uncertain:1

Mar 16, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

not provided

Uncertain:1

Jan 29, 2025

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); Missense variant in a gene in which most reported pathogenic variants are truncating/loss of function; Has not been previously published as pathogenic or benign to our knowledge

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.90

BayesDel_addAF

Benign

-0.0035

BayesDel_noAF

Benign

-0.14

CADD

Benign

(source)

DANN

Benign

0.96

Eigen

Pathogenic

0.88

Eigen_PC

Pathogenic

0.84

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.90

M_CAP

Benign

0.035

MetaRNN

Uncertain

0.44

MetaSVM

Uncertain

0.0075

MutationAssessor

Uncertain

2.9

PhyloP100

8.0

PrimateAI

Uncertain

0.56

PROVEAN

Pathogenic

-6.1

REVEL

Uncertain

0.52

Sift

Pathogenic

0.0

Polyphen

1.0

Vest4

0.56

MVP

0.63

MPC

0.52

ClinPred

0.47

GERP RS

6.0

Mutation Taster

=54/46

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