NM_001267550.2:c.41010T>C

Variant names:

• chr2-178636717-A-G
• rs193191368
• NM_001267550.2:c.41010T>C

Variant summary

Our verdict is Benign. The variant received -17 ACMG points: 0P and 17B. BP4_Strong BP6_Very_Strong BP7 BS1

The NM_001267550.2(TTN):​c.41010T>C​(p.Asp13670Asp) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000168 in 1,613,152 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.00081 (1 hom., cov: 32)
  • Exomes 𝑓: 0.00010 (1 hom.)
• Consequence: TTN NM_001267550.2 synonymous
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:14
• Conservation: PhyloP100: 0.155
• 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]

ACMG classification

Our verdict: Benign. The variant received -17 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.52).
• BP6: Variant 2-178636717-A-G is Benign according to our data. Variant chr2-178636717-A-G is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 46942.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=0.155 with no splicing effect.
• BS1: Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000815 (124/152210) while in subpopulation AFR AF = 0.00284 (118/41574). AF 95% confidence interval is 0.00242. There are 1 homozygotes in GnomAd4. There are 51 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

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.41010T>C	p.Asp13670Asp	synonymous	Exon 225 of 363	NP_001254479.2	Q8WZ42-12
	TTN	NM_001256850.1		c.36087T>C	p.Asp12029Asp	synonymous	Exon 175 of 313	NP_001243779.1	Q8WZ42-1
	TTN	NM_133378.4		c.33306T>C	p.Asp11102Asp	synonymous	Exon 174 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.41010T>C	p.Asp13670Asp	synonymous	Exon 225 of 363	ENSP00000467141.1	Q8WZ42-12
	TTN	ENST00000446966.2	TSL:1	c.40854T>C	p.Asp13618Asp	synonymous	Exon 223 of 361	ENSP00000408004.2	A0A1B0GXE3
	TTN	ENST00000436599.2	TSL:1	c.40734T>C	p.Asp13578Asp	synonymous	Exon 223 of 361	ENSP00000405517.2	A0A0C4DG59

Frequencies

GnomAD3 genomes AF: 0.000809 AC: 123 AN: 152092 Hom.: 1 Cov.: 32

Gnomad AFR AF: 0.00282

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000328

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.000238 AC: 59 AN: 248292 AF XY: 0.000163

Gnomad AFR exome AF: 0.00323

Gnomad AMR exome AF: 0.000232

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: 0.000166

GnomAD4 exome AF: 0.000101 AC: 147 AN: 1460942 Hom.: 1 Cov.: 32 AF XY: 0.0000826 AC XY: 60 AN XY: 726750

African (AFR) AF: 0.00335 AC: 112 AN: 33444

American (AMR) AF: 0.000179 AC: 8 AN: 44698

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26112

East Asian (EAS) AF: 0.00 AC: 0 AN: 39592

South Asian (SAS) AF: 0.0000464 AC: 4 AN: 86234

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53364

Middle Eastern (MID) AF: 0.000174 AC: 1 AN: 5758

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111418

Other (OTH) AF: 0.000315 AC: 19 AN: 60322

GnomAD4 genome AF: 0.000815 AC: 124 AN: 152210 Hom.: 1 Cov.: 32 AF XY: 0.000685 AC XY: 51 AN XY: 74414

African (AFR) AF: 0.00284 AC: 118 AN: 41574

American (AMR) AF: 0.000328 AC: 5 AN: 15266

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 5158

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10618

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

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 67978

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

Alfa AF: 0.000780 Hom.: 0

Bravo AF: 0.00110

Asia WGS AF: 0.000289 AC: 1 AN: 3476

ClinVar

ClinVar submissions

Significance: Benign/Likely benign

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	-	4	not provided (4)
-	-	3	not specified (3)
-	-	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	Cardiomyopathy (1)
-	-	1	Cardiovascular phenotype (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	-0.52
CADD	Benign	0.96
DANN	Benign	0.68
PhyloP100		0.15
Mutation Taster		=90/10	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: rs193191368; hg19: chr2-179501444;