chr2-178576364-A-G

Variant names:

• chr2-178576364-A-G
• rs182679164
• NM_001267550.2:c.69768T>C

Variant summary

Our verdict is Benign. The variant received -13 ACMG points: 0P and 13B. BP4_Strong BP6_Very_Strong BP7

The NM_001267550.2(TTN):​c.69768T>C​(p.Ser23256Ser) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000295 in 1,558,290 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 0.000053 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000027 (0 hom.)
• Consequence: TTN NM_001267550.2 synonymous
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:3
• Conservation: PhyloP100: 0.205
• Publications: 0 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 -13 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.51).
• BP6: Variant 2-178576364-A-G is Benign according to our data. Variant chr2-178576364-A-G is described in ClinVar as Likely_benign. ClinVar VariationId is 413184.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=0.205 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001267550.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTN	NM_001267550.2	MANE Select	c.69768T>C	p.Ser23256Ser	synonymous	Exon 326 of 363	NP_001254479.2	Q8WZ42-12
	TTN	NM_001256850.1		c.64845T>C	p.Ser21615Ser	synonymous	Exon 276 of 313	NP_001243779.1	Q8WZ42-1
	TTN	NM_133378.4		c.62064T>C	p.Ser20688Ser	synonymous	Exon 275 of 312	NP_596869.4	Q8WZ42-11

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTN	ENST00000589042.5	TSL:5 MANE Select	c.69768T>C	p.Ser23256Ser	synonymous	Exon 326 of 363	ENSP00000467141.1	Q8WZ42-12
	TTN	ENST00000446966.2	TSL:1	c.69612T>C	p.Ser23204Ser	synonymous	Exon 324 of 361	ENSP00000408004.2	A0A1B0GXE3
	TTN	ENST00000436599.2	TSL:1	c.69492T>C	p.Ser23164Ser	synonymous	Exon 324 of 361	ENSP00000405517.2	A0A0C4DG59

Frequencies

GnomAD3 genomes AF: 0.0000526 AC: 8 AN: 152104 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000969

Gnomad SAS AF: 0.000414

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.000478

GnomAD2 exomes AF: 0.000102 AC: 20 AN: 196990 AF XY: 0.0000749

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00110

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000270 AC: 38 AN: 1406068 Hom.: 0 Cov.: 36 AF XY: 0.0000316 AC XY: 22 AN XY: 695888

African (AFR) AF: 0.00 AC: 0 AN: 30796

American (AMR) AF: 0.00 AC: 0 AN: 31946

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 22560

East Asian (EAS) AF: 0.000739 AC: 29 AN: 39252

South Asian (SAS) AF: 0.0000662 AC: 5 AN: 75544

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 51134

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5482

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1091400

Other (OTH) AF: 0.0000690 AC: 4 AN: 57954

GnomAD4 genome AF: 0.0000526 AC: 8 AN: 152222 Hom.: 0 Cov.: 32 AF XY: 0.0000672 AC XY: 5 AN XY: 74404

African (AFR) AF: 0.00 AC: 0 AN: 41578

American (AMR) AF: 0.00 AC: 0 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.000972 AC: 5 AN: 5146

South Asian (SAS) AF: 0.000414 AC: 2 AN: 4826

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10622

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67982

Other (OTH) AF: 0.000473 AC: 1 AN: 2112

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000227

Asia WGS AF: 0.000867 AC: 3 AN: 3476

ClinVar

ClinVar submissions

Significance: Likely benign

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	-	1	Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G (1)
-	-	1	Cardiovascular phenotype (1)
-	-	1	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.51
CADD	Benign	0.41
DANN	Benign	0.60
PhyloP100		0.20
Mutation Taster		=74/26	polymorphism

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: rs182679164; hg19: chr2-179441091; COSMIC: COSV60120383; COSMIC: COSV60120383;