rs72646877

Variant names:

• chr2-178579071-A-G
• rs72646877
• NM_001267550.2:c.67959T>C

Your query was ambiguous. Multiple possible variants found:

• chr2-178579071-A-G
• chr2-178579071-A-T

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.67959T>C​(p.Phe22653Phe) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000162 in 1,613,196 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 0.00011 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00017 (0 hom.)
• Consequence: TTN NM_001267550.2 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4 B:8
• Conservation: PhyloP100: 3.07
• 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]

ENSG00000270574 (HGNC:):

ACMG classification

Our verdict: Likely_benign. The variant received -4 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.4).
• BP6: Variant 2-178579071-A-G is Benign according to our data. Variant chr2-178579071-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 262330.
• BP7: Synonymous conserved (PhyloP=3.07 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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTN	NM_001267550.2	MANE Select	c.67959T>C	p.Phe22653Phe	synonymous	Exon 320 of 363	NP_001254479.2	Q8WZ42-12
	TTN	NM_001256850.1		c.63036T>C	p.Phe21012Phe	synonymous	Exon 270 of 313	NP_001243779.1	Q8WZ42-1
	TTN	NM_133378.4		c.60255T>C	p.Phe20085Phe	synonymous	Exon 269 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.67959T>C	p.Phe22653Phe	synonymous	Exon 320 of 363	ENSP00000467141.1	Q8WZ42-12
	TTN	ENST00000446966.2	TSL:1	c.67803T>C	p.Phe22601Phe	synonymous	Exon 318 of 361	ENSP00000408004.2	A0A1B0GXE3
	TTN	ENST00000436599.2	TSL:1	c.67683T>C	p.Phe22561Phe	synonymous	Exon 318 of 361	ENSP00000405517.2	A0A0C4DG59

Frequencies

GnomAD3 genomes AF: 0.000112 AC: 17 AN: 152052 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

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: 0.000162

Gnomad OTH AF: 0.00144

GnomAD2 exomes AF: 0.0000483 AC: 12 AN: 248210 AF XY: 0.0000446

Gnomad AFR exome AF: 0.0000646

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: 0.0000980

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000167 AC: 244 AN: 1461144 Hom.: 0 Cov.: 33 AF XY: 0.000149 AC XY: 108 AN XY: 726864

African (AFR) AF: 0.0000299 AC: 1 AN: 33446

American (AMR) AF: 0.00 AC: 0 AN: 44700

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26122

East Asian (EAS) AF: 0.00 AC: 0 AN: 39574

South Asian (SAS) AF: 0.00 AC: 0 AN: 86246

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53384

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.000215 AC: 239 AN: 1111566

Other (OTH) AF: 0.0000663 AC: 4 AN: 60344

GnomAD4 genome AF: 0.000112 AC: 17 AN: 152052 Hom.: 0 Cov.: 32 AF XY: 0.0000539 AC XY: 4 AN XY: 74260

African (AFR) AF: 0.0000483 AC: 2 AN: 41416

American (AMR) AF: 0.0000655 AC: 1 AN: 15258

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 5154

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

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10622

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

European-Non Finnish (NFE) AF: 0.000162 AC: 11 AN: 67984

Other (OTH) AF: 0.00144 AC: 3 AN: 2090

Alfa AF: 0.000136 Hom.: 0

Bravo AF: 0.0000831

EpiCase AF: 0.000109

EpiControl AF: 0.0000593

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	-	3	not specified (3)
-	1	1	not provided (2)
-	1	-	Autosomal recessive limb-girdle muscular dystrophy type 2J (1)
-	-	1	Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G (1)
-	-	1	Cardiovascular phenotype (1)
-	1	-	Dilated cardiomyopathy 1G (1)
-	1	-	Early-onset myopathy with fatal cardiomyopathy (1)
-	-	1	Myopathy, myofibrillar, 9, with early respiratory failure (1)
-	-	1	Tibial muscular dystrophy (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.40
CADD	Benign	16
DANN	Benign	0.87
PhyloP100		3.1
Mutation Taster		=31/69	disease causing

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: rs72646877; hg19: chr2-179443798;