rs727505072

Variant names:

• chr2-178539261-T-C
• rs727505072
• ENST00000419746.5:n.1211T>C

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP6

The ENST00000419746.5(TTN-AS1):​n.1211T>C variant causes a non coding transcript exon change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000236 in 1,611,578 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).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000025 (0 hom.)
• Consequence: TTN-AS1 ENST00000419746.5 non_coding_transcript_exon
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 0.729
• Publications: 0 publications found

Genes affected

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 (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: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
• early-onset myopathy with fatal cardiomyopathy

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, G2P
• 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: Labcorp Genetics (formerly Invitae), Orphanet, ClinGen, Ambry Genetics
• tibial muscular dystrophy

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

  Inheritance: AR Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Orphanet
• hypertrophic cardiomyopathy 9

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

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• 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

ACMG classification

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

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.83).
• BP6: Variant 2-178539261-T-C is Benign according to our data. Variant chr2-178539261-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 179713.

Variant Effect in Transcripts

ACMG analysis was done for transcript: ENST00000419746.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTN	NM_001267550.2	MANE Select	c.98684-10A>G		intron	N/A	NP_001254479.2
	TTN-AS1	NR_038272.1		n.1211T>C		non_coding_transcript_exon	Exon 5 of 17
	TTN	NM_001256850.1		c.93761-10A>G		intron	N/A	NP_001243779.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTN-AS1	ENST00000419746.5	TSL:1	n.1211T>C		non_coding_transcript_exon	Exon 5 of 17
	TTN	ENST00000589042.5	TSL:5 MANE Select	c.98684-10A>G		intron	N/A	ENSP00000467141.1
	TTN	ENST00000446966.2	TSL:1	c.98528-10A>G		intron	N/A	ENSP00000408004.2

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152192 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000482

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: 0.00000404 AC: 1 AN: 247768 AF XY: 0.00000744

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: 0.00000891

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000247 AC: 36 AN: 1459386 Hom.: 0 Cov.: 33 AF XY: 0.0000289 AC XY: 21 AN XY: 725672

African (AFR) AF: 0.0000300 AC: 1 AN: 33384

American (AMR) AF: 0.00 AC: 0 AN: 44620

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25984

East Asian (EAS) AF: 0.00 AC: 0 AN: 39636

South Asian (SAS) AF: 0.00 AC: 0 AN: 86182

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53310

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5756

European-Non Finnish (NFE) AF: 0.0000306 AC: 34 AN: 1110250

Other (OTH) AF: 0.0000166 AC: 1 AN: 60264

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152192 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74356

African (AFR) AF: 0.0000482 AC: 2 AN: 41454

American (AMR) AF: 0.00 AC: 0 AN: 15278

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5196

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10622

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68022

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.0000740 Hom.: 0

Bravo AF: 0.0000189

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not specified Uncertain:1

Dec 08, 2017

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.90980-10A>G variant in TTN has not been previously reported in individuals with cardiomyopathy, but has been identified in 1/110805 European chromosomes b y the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbS NP rs72750572). This variant is located in the 3' splice region. Computational t ools do not suggest an impact to splicing. However, this information is not pred ictive enough to rule out pathogenicity. In summary, the clinical significance o f the c.90980-10A>G variant is uncertain. ACMG/AMP Criteria applied: PM2; BP4.

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

Nov 22, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.83
CADD	Benign	12
DANN	Benign	0.71
PhyloP100		0.73
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Mutation Taster		=99/1	polymorphism

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

Other links and lift over

dbSNP: rs727505072; hg19: chr2-179403988;