rs1280095100

chr2-178658135-G-A

Variant summary

Our verdict is Benign. Variant got -13 ACMG points: 0P and 13B. BP4_Strong BP6_Very_Strong BP7

The NM_001267550.2(TTN):c.37734C>T(p.Ala12578=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000628 in 1,433,444 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 Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.000021 (0 hom., cov: 18)
  • Exomes 𝑓: 0.0000063 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: TTN NM_001267550.2 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 0.140

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 Benign. Variant got -13 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.85).
• BP6: Variant 2-178658135-G-A is Benign according to our data. Variant chr2-178658135-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 535231.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=0.14 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2	c.37734C>T	p.Ala12578=	synonymous_variant	186/363	ENST00000589042.5
LOC124906100	XR_007087318.1	n.2185+13634G>A		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000589042.5	c.37734C>T	p.Ala12578=	synonymous_variant	186/363	5	NM_001267550.2	P1
TTN-AS1	ENST00000659121.1	n.502+60454G>A		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes AF: 0.00 AC: 3 AN: 144098 Hom.: 0 Cov.: 18 FAILED QC

Gnomad AFR AF: 0.0000266

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000731

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: 0.0000150

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000628 AC: 9 AN: 1433444 Hom.: 0 Cov.: 31 AF XY: 0.00000701 AC XY: 5 AN XY: 713230

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000119

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000723

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Data not reliable, filtered out with message: AS_VQSR AF: 0.0000208 AC: 3 AN: 144098 Hom.: 0 Cov.: 18 AF XY: 0.0000143 AC XY: 1 AN XY: 69948

Gnomad4 AFR AF: 0.0000266

Gnomad4 AMR AF: 0.0000731

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000150

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Likely 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

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Oct 05, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.85
Cadd	Benign	1.5
Dann	Benign	0.76

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1280095100; hg19: chr2-179522862;