chr2-178702578-A-G

Variant names:

• chr2-178702578-A-G
• rs762141482
• NM_001267550.2:c.30309T>C

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Moderate BP6 BP7

The NM_001267550.2(TTN):​c.30309T>C​(p.Phe10103Phe) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000143 in 1,613,844 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000079 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00015 (0 hom.)
• Consequence: TTN NM_001267550.2 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:5
• Conservation: PhyloP100: 0.808
• 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 -4 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.45).
• BP6: Variant 2-178702578-A-G is Benign according to our data. Variant chr2-178702578-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 282500.
• BP7: Synonymous conserved (PhyloP=0.808 with no splicing effect.

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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTN	NM_001267550.2	MANE Select	c.30309T>C	p.Phe10103Phe	synonymous	Exon 107 of 363	NP_001254479.2
	TTN	NM_001256850.1		c.29358T>C	p.Phe9786Phe	synonymous	Exon 105 of 313	NP_001243779.1
	TTN	NM_133378.4		c.26577T>C	p.Phe8859Phe	synonymous	Exon 104 of 312	NP_596869.4

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTN	ENST00000589042.5	TSL:5 MANE Select	c.30309T>C	p.Phe10103Phe	synonymous	Exon 107 of 363	ENSP00000467141.1
	TTN	ENST00000446966.2	TSL:1	c.30309T>C	p.Phe10103Phe	synonymous	Exon 107 of 361	ENSP00000408004.2
	TTN	ENST00000436599.2	TSL:1	c.30033T>C	p.Phe10011Phe	synonymous	Exon 105 of 361	ENSP00000405517.2

Frequencies

GnomAD3 genomes AF: 0.0000789 AC: 12 AN: 152138 Hom.: 0 Cov.: 32

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: 0.0000943

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000162

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.000185 AC: 46 AN: 249274 AF XY: 0.000177

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: 0.0000928

Gnomad NFE exome AF: 0.000372

Gnomad OTH exome AF: 0.000330

GnomAD4 exome AF: 0.000149 AC: 218 AN: 1461706 Hom.: 0 Cov.: 31 AF XY: 0.000151 AC XY: 110 AN XY: 727134

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.0000936 AC: 5 AN: 53400

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

European-Non Finnish (NFE) AF: 0.000185 AC: 206 AN: 1111866

Other (OTH) AF: 0.000116 AC: 7 AN: 60374

GnomAD4 genome AF: 0.0000789 AC: 12 AN: 152138 Hom.: 0 Cov.: 32 AF XY: 0.0000807 AC XY: 6 AN XY: 74318

African (AFR) AF: 0.00 AC: 0 AN: 41426

American (AMR) AF: 0.00 AC: 0 AN: 15272

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5200

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

European-Finnish (FIN) AF: 0.0000943 AC: 1 AN: 10600

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

European-Non Finnish (NFE) AF: 0.000162 AC: 11 AN: 68020

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

Alfa AF: 0.000165 Hom.: 0

Bravo AF: 0.0000680

EpiCase AF: 0.000218

EpiControl AF: 0.000178

ClinVar

ClinVar submissions as Germline

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

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

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.45
CADD	Benign	3.9
DANN	Benign	0.68
PhyloP100		0.81
PromoterAI		0.026	Neutral
Mutation Taster		=78/22	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: rs762141482; hg19: chr2-179567305;