2-178698916-TAAAA-T

Position:

• chr2-178698916-TAAAA-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP6_Moderate

The NM_001267550.2(TTN):​c.30683-6_30683-3del variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000054 in 1,313,990 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.000012 (0 hom., cov: 30)
  • Exomes 𝑓: 0.000057 (0 hom.)
• Consequence: TTN NM_001267550.2 splice_region, splice_polypyrimidine_tract, intron
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 3.01

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]

LOC124906100 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• BP6: Variant 2-178698916-TAAAA-T is Benign according to our data. Variant chr2-178698916-TAAAA-T is described in ClinVar as [Likely_benign]. Clinvar id is 282616.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2	c.30683-6_30683-3del		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000589042.5	NP_001254479.2
LOC124906100	XR_007087318.1	n.2186-14826_2186-14823del		intron_variant, non_coding_transcript_variant
LOC124907912	XR_007087321.1	n.7314+3477_7314+3480del		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5	c.30683-6_30683-3del		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		5	NM_001267550.2	ENSP00000467141	P1
TTN-AS1	ENST00000659121.1	n.503-35576_503-35573del		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes AF: 0.0000117 AC: 1 AN: 85112 Hom.: 0 Cov.: 30

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000323

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

GnomAD4 exome AF: 0.0000570 AC: 70 AN: 1228878 Hom.: 0 AF XY: 0.0000610 AC XY: 37 AN XY: 606250

Gnomad4 AFR exome AF: 0.000192

Gnomad4 AMR exome AF: 0.000341

Gnomad4 ASJ exome AF: 0.0000468

Gnomad4 EAS exome AF: 0.0000614

Gnomad4 SAS exome AF: 0.000132

Gnomad4 FIN exome AF: 0.000121

Gnomad4 NFE exome AF: 0.0000378

Gnomad4 OTH exome AF: 0.000117

GnomAD4 genome AF: 0.0000117 AC: 1 AN: 85112 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 40612

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000323

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000113

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Eurofins Ntd Llc (ga)

Aug 11, 2015

- -

Computational scores

Source: dbNSFP v4.3

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

LitVar

Other links and lift over

dbSNP: rs368277751; hg19: chr2-179563643;