rs878854300

chr2-178662773-G-Achr2-178662773-G-T

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 1P and 6B. PP2 BP4_Strong BP6_Moderate

The NM_001267550.2(TTN):c.36830C>T(p.Ala12277Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. In-silico tool predicts a benign outcome for this variant. 11/14 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.00012 (0 hom., cov: 20)
  • Exomes 𝑓: 0.000084 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: TTN NM_001267550.2 missense
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -0.638

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 -5 ACMG points.

• PP2: Missense variant where missense usually causes diseases, TTN
• BP4: Computational evidence support a benign effect (MetaRNN=0.015921652).
• BP6: Variant 2-178662773-G-A is Benign according to our data. Variant chr2-178662773-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 238755.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2	c.36830C>T	p.Ala12277Val	missense_variant	175/363	ENST00000589042.5
LOC124906100	XR_007087318.1	n.2185+18272G>A		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000589042.5	c.36830C>T	p.Ala12277Val	missense_variant	175/363	5	NM_001267550.2	P1
TTN-AS1	ENST00000659121.1	n.502+65092G>A		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes AF: 0.00 AC: 16 AN: 134780 Hom.: 0 Cov.: 20 FAILED QC

Gnomad AFR AF: 0.000282

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000152

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: 0.0000636

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000519 AC: 29 AN: 55920 Hom.: 0 AF XY: 0.000713 AC XY: 20 AN XY: 28034

Gnomad AFR exome AF: 0.000568

Gnomad AMR exome AF: 0.000557

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000127

Gnomad SAS exome AF: 0.00231

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000138

Gnomad OTH exome AF: 0.00103

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.0000837 AC: 102 AN: 1218788 Hom.: 0 Cov.: 17 AF XY: 0.000103 AC XY: 63 AN XY: 609500

Gnomad4 AFR exome AF: 0.000252

Gnomad4 AMR exome AF: 0.000166

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000267

Gnomad4 SAS exome AF: 0.000775

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000248

Gnomad4 OTH exome AF: 0.0000775

GnomAD4 genome Data not reliable, filtered out with message: AS_VQSR AF: 0.000119 AC: 16 AN: 134866 Hom.: 0 Cov.: 20 AF XY: 0.0000927 AC XY: 6 AN XY: 64702

Gnomad4 AFR AF: 0.000281

Gnomad4 AMR AF: 0.000152

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000636

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

Nov 01, 2022

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.33	T
BayesDel_noAF	Benign	-0.71
Cadd	Benign	5.6
Dann	Benign	0.72
Eigen	Benign	-1.0
Eigen_PC	Benign	-1.0
FATHMM_MKL	Benign	0.00091	N
LIST_S2	Benign	0.21	T
M_CAP	Benign	0.026	D
MetaRNN	Benign	0.016	T
MetaSVM	Benign	-1.0	T
MutationTaster	Benign	1.0	N;N;N;N;N;N
Vest4		0.030
MVP		0.25
MPC		0.083
ClinPred		0.0058	T
GERP RS		3.3

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: rs878854300; hg19: chr2-179527500;