2-178536584-CAAAA-CAAA

Variant names:

• chr2-178536584-CA-C
• rs397517782
• NM_001267550.2:c.100172-10delT

Variant summary

Our verdict is Benign. The variant received -8 ACMG points: 0P and 8B. BP6_Very_Strong

The NM_001267550.2(TTN):​c.100172-10delT variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000351 in 1,479,830 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000038 (0 hom.)
• Consequence: TTN NM_001267550.2 intron
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:2
• Conservation: PhyloP100: 1.72
• Publications: 1 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-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]

ACMG classification

Our verdict: Benign. The variant received -8 ACMG points.

• BP6: Variant 2-178536584-CA-C is Benign according to our data. Variant chr2-178536584-CA-C is described in ClinVar as Likely_benign. ClinVar VariationId is 994002.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2	c.100172-10delT		intron_variant	Intron 356 of 362	ENST00000589042.5	NP_001254479.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5	c.100172-10delT		intron_variant	Intron 356 of 362	5	NM_001267550.2	ENSP00000467141.1

Frequencies

GnomAD3 genomes AF: 0.0000132 AC: 2 AN: 151514 Hom.: 0 Cov.: 33

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: 0.0000295

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000943 AC: 14 AN: 148510 AF XY: 0.0000999

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000624

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000169

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000376 AC: 50 AN: 1328316 Hom.: 0 Cov.: 31 AF XY: 0.0000385 AC XY: 25 AN XY: 648868

African (AFR) AF: 0.0000338 AC: 1 AN: 29558

American (AMR) AF: 0.0000403 AC: 1 AN: 24836

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 19388

East Asian (EAS) AF: 0.00 AC: 0 AN: 37710

South Asian (SAS) AF: 0.0000321 AC: 2 AN: 62398

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 41004

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5234

European-Non Finnish (NFE) AF: 0.0000437 AC: 46 AN: 1053346

Other (OTH) AF: 0.00 AC: 0 AN: 54842

GnomAD4 genome AF: 0.0000132 AC: 2 AN: 151514 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 73948

African (AFR) AF: 0.00 AC: 0 AN: 41244

American (AMR) AF: 0.00 AC: 0 AN: 15228

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5184

South Asian (SAS) AF: 0.00 AC: 0 AN: 4826

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10394

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

European-Non Finnish (NFE) AF: 0.0000295 AC: 2 AN: 67862

Other (OTH) AF: 0.00 AC: 0 AN: 2082

Alfa AF: 0.000100 Hom.: 1

ClinVar

Significance: Likely benign

Submissions summary: Benign:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Sep 10, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Benign:1

Jul 25, 2019

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.7
Mutation Taster		=100/0	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		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: rs397517782; hg19: chr2-179401311; COSMIC: COSV100634432; COSMIC: COSV100634432;