rs28626194

Variant names:

• chr2-178727218-A-C
• rs28626194
• NM_001267550.2:c.20147T>G

Your query was ambiguous. Multiple possible variants found:

• chr2-178727218-A-C
• chr2-178727218-A-T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_001267550.2(TTN):​c.20147T>G​(p.Met6716Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000186 in 1,613,250 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M6716K) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TTN NM_001267550.2 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 3.97
• Publications: 2 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]

ENSG00000267784 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

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.20147T>G	p.Met6716Arg	missense	Exon 69 of 363	NP_001254479.2	Q8WZ42-12
	TTN	NM_001256850.1		c.19196T>G	p.Met6399Arg	missense	Exon 67 of 313	NP_001243779.1	Q8WZ42-1
	TTN	NM_133378.4		c.16415T>G	p.Met5472Arg	missense	Exon 66 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.20147T>G	p.Met6716Arg	missense	Exon 69 of 363	ENSP00000467141.1	Q8WZ42-12
	TTN	ENST00000446966.2	TSL:1	c.20147T>G	p.Met6716Arg	missense	Exon 69 of 361	ENSP00000408004.2	A0A1B0GXE3
	TTN	ENST00000436599.2	TSL:1	c.19871T>G	p.Met6624Arg	missense	Exon 67 of 361	ENSP00000405517.2	A0A0C4DG59

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000805 AC: 2 AN: 248332 AF XY: 0.0000148

Gnomad AFR exome AF: 0.000129

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: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461054 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 726782

African (AFR) AF: 0.0000299 AC: 1 AN: 33430

American (AMR) AF: 0.00 AC: 0 AN: 44686

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26112

East Asian (EAS) AF: 0.00 AC: 0 AN: 39664

South Asian (SAS) AF: 0.00 AC: 0 AN: 86210

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53386

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5758

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111460

Other (OTH) AF: 0.00 AC: 0 AN: 60348

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152196 Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2 AN XY: 74408

African (AFR) AF: 0.0000481 AC: 2 AN: 41564

American (AMR) AF: 0.00 AC: 0 AN: 15278

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3466

East Asian (EAS) AF: 0.00 AC: 0 AN: 5158

South Asian (SAS) AF: 0.00 AC: 0 AN: 4820

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10620

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67970

Other (OTH) AF: 0.00 AC: 0 AN: 2114

Alfa AF: 0.00 Hom.: 0

ExAC AF: 0.0000165 AC: 2

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.47
BayesDel_addAF	Benign	-0.16	T
BayesDel_noAF	Benign	-0.24
CADD	Benign	22
DANN	Benign	0.94
Eigen	Uncertain	0.65
Eigen_PC	Pathogenic	0.67
FATHMM_MKL	Uncertain	0.81	D
LIST_S2	Benign	0.72	T
M_CAP	Benign	0.023	T
MetaRNN	Uncertain	0.60	D
MetaSVM	Uncertain	-0.26	T
PhyloP100		4.0
PrimateAI	Uncertain	0.49	T
PROVEAN	Uncertain	-3.4	D
REVEL	Uncertain	0.48
Sift	Benign	0.26	T
Polyphen		0.98	D
Vest4		0.63
MutPred		0.71		Loss of stability (P = 0.07)
MVP		0.77
MPC		0.38
ClinPred		0.18	T
GERP RS		6.2
Mutation Taster		=46/54	disease causing

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: rs28626194; hg19: chr2-179591945;