NM_001267550.2:c.27592C>G

Variant names:

• chr2-178712330-G-C
• rs72648995
• NM_001267550.2:c.27592C>G

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_Strong BP6

The NM_001267550.2(TTN):​c.27592C>G​(p.Gln9198Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000229 in 1,613,470 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q9198R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000023 (0 hom.)
• Consequence: TTN NM_001267550.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:1
• Conservation: PhyloP100: 0.824
• 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]

LOC124906100 (HGNC:):

ACMG classification

Our verdict: Likely_benign. The variant received -5 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.026964724).
• BP6: Variant 2-178712330-G-C is Benign according to our data. Variant chr2-178712330-G-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 288760.

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.27592C>G	p.Gln9198Glu	missense	Exon 95 of 363	NP_001254479.2	Q8WZ42-12
	TTN	NM_001256850.1		c.26641C>G	p.Gln8881Glu	missense	Exon 93 of 313	NP_001243779.1	Q8WZ42-1
	TTN	NM_133378.4		c.23860C>G	p.Gln7954Glu	missense	Exon 92 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.27592C>G	p.Gln9198Glu	missense	Exon 95 of 363	ENSP00000467141.1	Q8WZ42-12
	TTN	ENST00000446966.2	TSL:1	c.27592C>G	p.Gln9198Glu	missense	Exon 95 of 361	ENSP00000408004.2	A0A1B0GXE3
	TTN	ENST00000436599.2	TSL:1	c.27316C>G	p.Gln9106Glu	missense	Exon 93 of 361	ENSP00000405517.2	A0A0C4DG59

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152140 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000196

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: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.000117 AC: 29 AN: 248590 AF XY: 0.0000816

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000841

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: 0.0000233 AC: 34 AN: 1461330 Hom.: 0 Cov.: 32 AF XY: 0.0000193 AC XY: 14 AN XY: 726910

African (AFR) AF: 0.00 AC: 0 AN: 33462

American (AMR) AF: 0.000716 AC: 32 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26118

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.00 AC: 0 AN: 86220

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53372

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111620

Other (OTH) AF: 0.0000331 AC: 2 AN: 60368

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152140 Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2 AN XY: 74308

African (AFR) AF: 0.00 AC: 0 AN: 41428

American (AMR) AF: 0.000196 AC: 3 AN: 15274

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 5192

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10610

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68020

Other (OTH) AF: 0.00 AC: 0 AN: 2088

Alfa AF: 0.000142 Hom.: 0

Bravo AF: 0.0000491

ExAC AF: 0.000108 AC: 13

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

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

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.067
BayesDel_addAF	Benign	-0.38	T
BayesDel_noAF	Benign	-0.40
CADD	Benign	20
DANN	Benign	0.90
Eigen	Benign	-0.32
Eigen_PC	Benign	-0.17
FATHMM_MKL	Benign	0.23	N
LIST_S2	Benign	0.75	T
M_CAP	Benign	0.0090	T
MetaRNN	Benign	0.027	T
MetaSVM	Benign	-0.93	T
PhyloP100		0.82
PrimateAI	Benign	0.38	T
PROVEAN	Benign	-1.5	N
REVEL	Benign	0.098
Sift	Benign	0.76	T
Polyphen		0.16	B
Vest4		0.31
MutPred		0.51		Loss of sheet (P = 0.0817)
MVP		0.24
MPC		0.10
ClinPred		0.041	T
GERP RS		5.9
Mutation Taster		=80/20	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: rs72648995; hg19: chr2-179577057;