rs375209383

Variant names:

• chr2-178710835-G-A
• rs375209383
• NM_001267550.2:c.28262C>T

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BP4

The NM_001267550.2(TTN):​c.28262C>T​(p.Thr9421Met) variant causes a missense change. The variant allele was found at a frequency of 0.0000719 in 1,613,838 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 11/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. T9421T) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000046 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000075 (0 hom.)
• Consequence: TTN NM_001267550.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4 B:1
• Conservation: PhyloP100: 6.71
• 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]

LOC124906100 (HGNC:):

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.267031).

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.28262C>T	p.Thr9421Met	missense	Exon 98 of 363	NP_001254479.2	Q8WZ42-12
	TTN	NM_001256850.1		c.27311C>T	p.Thr9104Met	missense	Exon 96 of 313	NP_001243779.1	Q8WZ42-1
	TTN	NM_133378.4		c.24530C>T	p.Thr8177Met	missense	Exon 95 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.28262C>T	p.Thr9421Met	missense	Exon 98 of 363	ENSP00000467141.1	Q8WZ42-12
	TTN	ENST00000446966.2	TSL:1	c.28262C>T	p.Thr9421Met	missense	Exon 98 of 361	ENSP00000408004.2	A0A1B0GXE3
	TTN	ENST00000436599.2	TSL:1	c.27986C>T	p.Thr9329Met	missense	Exon 96 of 361	ENSP00000405517.2	A0A0C4DG59

Frequencies

GnomAD3 genomes AF: 0.0000460 AC: 7 AN: 152098 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000386

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.0000943

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000441

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000924 AC: 23 AN: 248852 AF XY: 0.0000741

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000445

Gnomad FIN exome AF: 0.0000464

Gnomad NFE exome AF: 0.0000710

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000746 AC: 109 AN: 1461622 Hom.: 0 Cov.: 31 AF XY: 0.0000756 AC XY: 55 AN XY: 727092

African (AFR) AF: 0.0000299 AC: 1 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.000806 AC: 32 AN: 39698

South Asian (SAS) AF: 0.000267 AC: 23 AN: 86256

European-Finnish (FIN) AF: 0.0000187 AC: 1 AN: 53398

Middle Eastern (MID) AF: 0.000173 AC: 1 AN: 5768

European-Non Finnish (NFE) AF: 0.0000423 AC: 47 AN: 1111808

Other (OTH) AF: 0.0000663 AC: 4 AN: 60372

GnomAD4 genome AF: 0.0000460 AC: 7 AN: 152216 Hom.: 0 Cov.: 33 AF XY: 0.0000537 AC XY: 4 AN XY: 74424

African (AFR) AF: 0.0000241 AC: 1 AN: 41538

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

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

East Asian (EAS) AF: 0.000387 AC: 2 AN: 5170

South Asian (SAS) AF: 0.00 AC: 0 AN: 4822

European-Finnish (FIN) AF: 0.0000943 AC: 1 AN: 10606

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

European-Non Finnish (NFE) AF: 0.0000441 AC: 3 AN: 68014

Other (OTH) AF: 0.00 AC: 0 AN: 2108

Alfa AF: 0.0000565 Hom.: 0

Bravo AF: 0.0000756

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000120 AC: 1

ExAC AF: 0.000107 AC: 13

EpiCase AF: 0.00

EpiControl AF: 0.000178

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	3	-	not provided (3)
-	1	-	Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G (1)
-	-	1	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.22	T
BayesDel_noAF	Benign	-0.24
CADD	Benign	21
DANN	Benign	0.62
Eigen	Benign	-0.031
Eigen_PC	Benign	0.019
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Benign	0.71	T
M_CAP	Benign	0.067	D
MetaRNN	Benign	0.27	T
MetaSVM	Benign	-0.35	T
PhyloP100		6.7
PrimateAI	Uncertain	0.59	T
PROVEAN	Uncertain	-3.4	D
REVEL	Uncertain	0.38
Sift	Uncertain	0.017	D
Polyphen		0.16	B
Vest4		0.34
MVP		0.61
MPC		0.11
ClinPred		0.11	T
GERP RS		5.3
Mutation Taster		=89/11	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: rs375209383; hg19: chr2-179575562; COSMIC: COSV59920650;