2-178766630-TAAA-TAAAA

Variant names:

• chr2-178766630-T-TA
• rs201990196
• NM_001267550.2:c.9472-19dupT

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP6_Moderate

The NM_001267550.2(TTN):​c.9472-19dupT variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000119 in 1,593,294 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Benign (★).

• Frequency:
  • Genomes: 𝑓 0.000073 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: TTN NM_001267550.2 intron
• Clinical Significance: Benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 1.44
• 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: Likely_benign. The variant received -2 ACMG points.

• BP6: Variant 2-178766630-T-TA is Benign according to our data. Variant chr2-178766630-T-TA is described in ClinVar as Benign. ClinVar VariationId is 1552931.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2	c.9472-19dupT		intron_variant	Intron 40 of 362	ENST00000589042.5	NP_001254479.2
TTN	NM_133379.5	c.9472-19dupT		intron_variant	Intron 40 of 45	ENST00000360870.10	NP_596870.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5	c.9472-19_9472-18insT		intron_variant	Intron 40 of 362	5	NM_001267550.2	ENSP00000467141.1
TTN	ENST00000360870.10	c.9472-19_9472-18insT		intron_variant	Intron 40 of 45	5	NM_133379.5	ENSP00000354117.4

Frequencies

GnomAD3 genomes AF: 0.0000729 AC: 11 AN: 150948 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000219

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

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: 0.00000819 AC: 2 AN: 244338 AF XY: 0.0000151

Gnomad AFR exome AF: 0.0000626

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: 0.00

Gnomad OTH exome AF: 0.000167

GnomAD4 exome AF: 0.00000555 AC: 8 AN: 1442244 Hom.: 0 Cov.: 27 AF XY: 0.00000417 AC XY: 3 AN XY: 718716

African (AFR) AF: 0.000121 AC: 4 AN: 33054

American (AMR) AF: 0.00 AC: 0 AN: 44530

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25988

East Asian (EAS) AF: 0.00 AC: 0 AN: 39428

South Asian (SAS) AF: 0.00 AC: 0 AN: 85780

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52954

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5570

European-Non Finnish (NFE) AF: 0.00000274 AC: 3 AN: 1095210

Other (OTH) AF: 0.0000167 AC: 1 AN: 59730

GnomAD4 genome AF: 0.0000728 AC: 11 AN: 151050 Hom.: 0 Cov.: 32 AF XY: 0.0000136 AC XY: 1 AN XY: 73730

African (AFR) AF: 0.000219 AC: 9 AN: 41184

American (AMR) AF: 0.00 AC: 0 AN: 14816

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

East Asian (EAS) AF: 0.000193 AC: 1 AN: 5178

South Asian (SAS) AF: 0.00 AC: 0 AN: 4624

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10532

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 67934

Other (OTH) AF: 0.00 AC: 0 AN: 2108

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Oct 27, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.4

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: rs201990196; hg19: chr2-179631357;