rs199705789

chr2-178644611-G-T

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 3P and 4B. PM2 PP2 BP4_Strong

The NM_001267550.2(TTN):c.40414C>A(p.Pro13472Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000192 in 1,564,868 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: TTN NM_001267550.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: -0.768

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

Verdict is Likely_benign. Variant got -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, TTN
• BP4: Computational evidence support a benign effect (MetaRNN=0.03168735).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2	c.40414C>A	p.Pro13472Thr	missense_variant	218/363	ENST00000589042.5
LOC124906100	XR_007087318.1	n.2185+110G>T		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000589042.5	c.40414C>A	p.Pro13472Thr	missense_variant	218/363	5	NM_001267550.2	P1
TTN-AS1	ENST00000659121.1	n.502+46930G>T		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 151954 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: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000142 AC: 2 AN: 1412914 Hom.: 0 Cov.: 29 AF XY: 0.00000286 AC XY: 2 AN XY: 700182

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000183

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 151954 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74208

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	May 31, 2018	- -
Uncertain significance, criteria provided, single submitter	research	Biesecker Lab/Clinical Genomics Section, National Institutes of Health	Jun 24, 2013	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Nov 22, 2019	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.087
BayesDel_addAF	Benign	-0.19	T
BayesDel_noAF	Benign	-0.52
Cadd	Benign	1.3
Dann	Benign	0.52
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.026	N
LIST_S2	Benign	0.58	T;T;.;T;T
M_CAP	Benign	0.012	T
MetaRNN	Benign	0.032	T;T;T;T;T
MetaSVM	Benign	-1.0	T
MutationTaster	Benign	0.99	D;D;D;N;N;N
PrimateAI	Benign	0.35	T
PROVEAN	Benign	-0.36	N;.;.;.;N
REVEL	Benign	0.048
Sift	Benign	0.87	T;.;.;.;T
Polyphen		0.0010	.;.;B;B;.
Vest4		0.087
MVP		0.040
MPC		0.094
ClinPred		0.022	T
GERP RS		-8.5

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.17		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs199705789; hg19: chr2-179509338; COSMIC: COSV59960609; COSMIC: COSV59960609;