rs373732722

Variant names:

• chr2-178548303-A-G
• rs373732722
• NM_001267550.2:c.93323T>C

Your query was ambiguous. Multiple possible variants found:

• chr2-178548303-A-G
• chr2-178548303-A-C
• chr2-178548303-A-T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_Moderate BP6

The NM_001267550.2(TTN):​c.93323T>C​(p.Ile31108Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000062 in 1,613,876 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/20 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. I31108V) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000062 (1 hom.)
• Consequence: TTN NM_001267550.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:1
• Conservation: PhyloP100: 7.56
• Publications: 1 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: Likely_benign. The variant received -3 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.072277606).
• BP6: Variant 2-178548303-A-G is Benign according to our data. Variant chr2-178548303-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 467653.

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.93323T>C	p.Ile31108Thr	missense	Exon 339 of 363	NP_001254479.2	Q8WZ42-12
	TTN	NM_001256850.1		c.88400T>C	p.Ile29467Thr	missense	Exon 289 of 313	NP_001243779.1	Q8WZ42-1
	TTN	NM_133378.4		c.85619T>C	p.Ile28540Thr	missense	Exon 288 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.93323T>C	p.Ile31108Thr	missense	Exon 339 of 363	ENSP00000467141.1	Q8WZ42-12
	TTN	ENST00000446966.2	TSL:1	c.93167T>C	p.Ile31056Thr	missense	Exon 337 of 361	ENSP00000408004.2	A0A1B0GXE3
	TTN	ENST00000436599.2	TSL:1	c.93047T>C	p.Ile31016Thr	missense	Exon 337 of 361	ENSP00000405517.2	A0A0C4DG59

Frequencies

GnomAD3 genomes AF: 0.0000657 AC: 10 AN: 152146 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

Gnomad SAS AF: 0.000415

Gnomad FIN AF: 0.000188

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000441

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.000109 AC: 27 AN: 248454 AF XY: 0.000111

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000116

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000557

Gnomad FIN exome AF: 0.000557

Gnomad NFE exome AF: 0.0000267

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000616 AC: 90 AN: 1461612 Hom.: 1 Cov.: 34 AF XY: 0.0000743 AC XY: 54 AN XY: 727088

African (AFR) AF: 0.0000896 AC: 3 AN: 33472

American (AMR) AF: 0.000157 AC: 7 AN: 44720

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.000267 AC: 23 AN: 86258

European-Finnish (FIN) AF: 0.000393 AC: 21 AN: 53394

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000261 AC: 29 AN: 1111802

Other (OTH) AF: 0.000116 AC: 7 AN: 60368

GnomAD4 genome AF: 0.0000657 AC: 10 AN: 152264 Hom.: 0 Cov.: 32 AF XY: 0.0000940 AC XY: 7 AN XY: 74460

African (AFR) AF: 0.00 AC: 0 AN: 41568

American (AMR) AF: 0.000131 AC: 2 AN: 15286

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

East Asian (EAS) AF: 0.000193 AC: 1 AN: 5178

South Asian (SAS) AF: 0.000415 AC: 2 AN: 4814

European-Finnish (FIN) AF: 0.000188 AC: 2 AN: 10628

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

European-Non Finnish (NFE) AF: 0.0000441 AC: 3 AN: 67998

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

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.0000567

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000119 AC: 1

ExAC AF: 0.0000496 AC: 6

Asia WGS AF: 0.00260 AC: 9 AN: 3478

EpiCase AF: 0.0000545

EpiControl AF: 0.0000593

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	1	1	not provided (2)
-	1	-	Autosomal recessive limb-girdle muscular dystrophy type 2J;C1838244:Tibial muscular dystrophy;C1858763:Dilated cardiomyopathy 1G;C1861065:Hypertrophic cardiomyopathy 9;C1863599:Myopathy, myofibrillar, 9, with early respiratory failure;C2673677:Early-onset myopathy with fatal cardiomyopathy (1)
-	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	0.16
BayesDel_addAF	Benign	-0.33	T
BayesDel_noAF	Benign	-0.42
CADD	Benign	20
DANN	Benign	0.84
Eigen	Benign	0.094
Eigen_PC	Benign	0.18
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.84	T
M_CAP	Benign	0.016	T
MetaRNN	Benign	0.072	T
MetaSVM	Benign	-0.71	T
MutationAssessor	Benign	2.0	M
PhyloP100		7.6
PrimateAI	Benign	0.29	T
PROVEAN	Uncertain	-3.3	D
REVEL	Benign	0.26
Sift	Uncertain	0.011	D
Polyphen		0.0010	B
Vest4		0.29
MVP		0.48
MPC		0.11
ClinPred		0.13	T
GERP RS		5.7
Mutation Taster		=96/4	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: rs373732722; hg19: chr2-179413030; COSMIC: COSV60336710; COSMIC: COSV60336710;