rs2046778

Variant names:

• chr2-178807820-T-C
• rs2046778
• ENST00000412264.2:c.-13-3165A>G

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 0P and 10B. BP4_Moderate BA1

The ENST00000412264.2(TTN):​c.-13-3165A>G variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.248 in 151,766 control chromosomes in the GnomAD database, including 5,078 homozygotes. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: 𝑓 0.25 (5078 hom., cov: 31)
• Consequence: TTN ENST00000412264.2 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.66
• Publications: 5 publications found

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 Gene-Disease associations (from GenCC):

• dilated cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• dilated cardiomyopathy 1G

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• early-onset myopathy with fatal cardiomyopathy

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Labcorp Genetics (formerly Invitae)
• TTN-related myopathy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• myopathy, myofibrillar, 9, with early respiratory failure

  Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Orphanet, ClinGen, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• tibial muscular dystrophy

  Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: ClinGen, Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• autosomal recessive limb-girdle muscular dystrophy type 2J

  Inheritance: AR Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet, Labcorp Genetics (formerly Invitae)
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal recessive centronuclear myopathy

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• childhood-onset progressive contractures-limb-girdle weakness-muscle dystrophy syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• congenital myopathy

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
• hereditary skeletal muscle disorder

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
• hypertrophic cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• hypertrophic cardiomyopathy 9

  Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
• arrhythmogenic right ventricular cardiomyopathy

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Benign. The variant received -10 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.25).
• BA1: GnomAd4 highest subpopulation (AFR) allele frequency at 95% confidence interval = 0.316 is higher than 0.05.

Variant Effect in Transcripts

ACMG analysis was done for transcript: ENST00000412264.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
There are no transcript annotations for this variant.

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTN	ENST00000412264.2	TSL:3	c.-13-3165A>G		intron	N/A	ENSP00000394672.2	Q8WZ42-12

Frequencies

GnomAD3 genomes AF: 0.248 AC: 37625 AN: 151648 Hom.: 5071 Cov.: 31

Gnomad AFR AF: 0.320

Gnomad AMI AF: 0.114

Gnomad AMR AF: 0.218

Gnomad ASJ AF: 0.336

Gnomad EAS AF: 0.111

Gnomad SAS AF: 0.126

Gnomad FIN AF: 0.143

Gnomad MID AF: 0.316

Gnomad NFE AF: 0.242

Gnomad OTH AF: 0.295

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome AF: 0.248 AC: 37665 AN: 151766 Hom.: 5078 Cov.: 31 AF XY: 0.240 AC XY: 17783 AN XY: 74176

African (AFR) AF: 0.321 AC: 13242 AN: 41308

American (AMR) AF: 0.217 AC: 3315 AN: 15264

Ashkenazi Jewish (ASJ) AF: 0.336 AC: 1165 AN: 3464

East Asian (EAS) AF: 0.111 AC: 571 AN: 5128

South Asian (SAS) AF: 0.125 AC: 601 AN: 4806

European-Finnish (FIN) AF: 0.143 AC: 1512 AN: 10566

Middle Eastern (MID) AF: 0.313 AC: 92 AN: 294

European-Non Finnish (NFE) AF: 0.242 AC: 16449 AN: 67924

Other (OTH) AF: 0.292 AC: 614 AN: 2102

Alfa AF: 0.239 Hom.: 2389

Bravo AF: 0.261

Asia WGS AF: 0.143 AC: 498 AN: 3478

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.25
CADD	Benign	18
DANN	Benign	0.92
PhyloP100		2.7
PromoterAI		0.0085	Neutral

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs2046778; hg19: chr2-179672547;