rs397517781

Variant names:

• chr2-178537377-C-G
• rs397517781
• NM_001267550.2:c.99830G>C

Your query was ambiguous. Multiple possible variants found:

• chr2-178537377-C-G
• chr2-178537377-C-T

Variant summary

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

The NM_001267550.2(TTN):​c.99830G>C​(p.Gly33277Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000815 in 1,594,438 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. G33277E) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000076 (0 hom.)
• Consequence: TTN NM_001267550.2 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.91
• Publications: 5 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: Uncertain_significance. The variant received 0 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2	c.99830G>C	p.Gly33277Ala	missense_variant	Exon 355 of 363	ENST00000589042.5	NP_001254479.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5	c.99830G>C	p.Gly33277Ala	missense_variant	Exon 355 of 363	5	NM_001267550.2	ENSP00000467141.1

Frequencies

GnomAD3 genomes AF: 0.0000132 AC: 2 AN: 152042 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.0000294

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000419 AC: 1 AN: 238782 AF XY: 0.00

Gnomad AFR exome AF: 0.00

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: 0.00000921

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000763 AC: 11 AN: 1442396 Hom.: 0 Cov.: 33 AF XY: 0.00000280 AC XY: 2 AN XY: 714384

African (AFR) AF: 0.00 AC: 0 AN: 32904

American (AMR) AF: 0.00 AC: 0 AN: 43154

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25502

East Asian (EAS) AF: 0.00 AC: 0 AN: 39322

South Asian (SAS) AF: 0.00 AC: 0 AN: 83016

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52948

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5692

European-Non Finnish (NFE) AF: 0.0000100 AC: 11 AN: 1100358

Other (OTH) AF: 0.00 AC: 0 AN: 59500

GnomAD4 genome AF: 0.0000132 AC: 2 AN: 152042 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74260

African (AFR) AF: 0.00 AC: 0 AN: 41378

American (AMR) AF: 0.00 AC: 0 AN: 15256

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5190

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10588

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000294 AC: 2 AN: 68012

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00000432 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.88
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Uncertain	-0.080
CADD	Benign	20
DANN	Benign	0.95
Eigen	Pathogenic	0.95
Eigen_PC	Pathogenic	0.90
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.91	D;D;D;.;D;D;D
M_CAP	Benign	0.079	D
MetaRNN	Uncertain	0.46	T;T;T;T;T;T;T
MetaSVM	Uncertain	0.43	D
MutationAssessor	Pathogenic	3.3	.;.;.;M;.;.;M
PhyloP100		7.9
PrimateAI	Uncertain	0.63	T
PROVEAN	Pathogenic	-4.5	D;D;.;.;D;D;.
REVEL	Pathogenic	0.81
Sift	Pathogenic	0.0	D;D;.;.;D;D;.
Polyphen		1.0	.;.;.;D;.;.;D
Vest4		0.52
MVP		0.56
MPC		0.48
ClinPred		0.71	D
GERP RS		5.8
Mutation Taster		=57/43	polymorphism

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

Other links and lift over

dbSNP: rs397517781; hg19: chr2-179402104;