NM_001267550.2:c.66568G>C

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.

The NM_001267550.2(TTN):​c.66568G>C​(p.Gly22190Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000141 in 1,611,812 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00015 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

6
8
3

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:7

Conservation

PhyloP100: 7.86

Publications

1 publications found
Variant links:
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]

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.66568G>C p.Gly22190Arg missense_variant Exon 316 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.66568G>C p.Gly22190Arg missense_variant Exon 316 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152036
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000724
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000122
AC:
3
AN:
245838
AF XY:
0.00000750
show subpopulations
Gnomad AFR exome
AF:
0.0000655
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:
0.0000180
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000152
AC:
222
AN:
1459776
Hom.:
1
Cov.:
32
AF XY:
0.000157
AC XY:
114
AN XY:
726122
show subpopulations
African (AFR)
AF:
0.0000898
AC:
3
AN:
33418
American (AMR)
AF:
0.00
AC:
0
AN:
44570
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26084
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39386
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86080
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53240
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5754
European-Non Finnish (NFE)
AF:
0.000195
AC:
217
AN:
1110968
Other (OTH)
AF:
0.0000332
AC:
2
AN:
60276
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.495
Heterozygous variant carriers
0
12
24
36
48
60
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
20
40
60
80
100
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000329
AC:
5
AN:
152036
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74220
show subpopulations
African (AFR)
AF:
0.0000724
AC:
3
AN:
41420
American (AMR)
AF:
0.00
AC:
0
AN:
15250
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5152
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
67984
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000282
Hom.:
0
Bravo
AF:
0.0000151
ExAC
AF:
0.00000829
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:7
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:2
Jun 18, 2015
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Nov 18, 2019
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1
May 16, 2014
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Missense variants in the TTN gene are considered 'unclassified' if they are not previously reported in the literature and do not have >1% frequency in the population to be considered a polymorphism. Research indicates that truncating mutations in the TTN gene are expected to account for approximately 25% of familial and 18% of sporadic idiopathic DCM; however, truncating variants in the TTN gene have been reported in approximately 3% of reported control alleles. There has been little investigation into non-truncating variants. (Herman D et al. Truncations of titin causing dilated cardiomyopathy. N Eng J Med 366:619-628, 2012) The variant is found in DCM-CRDM panel(s). -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
May 31, 2016
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

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 Uncertain:1
Nov 04, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Uncertain:1
May 29, 2019
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.G13125R variant (also known as c.39373G>C), located in coding exon 143 of the TTN gene, results from a G to C substitution at nucleotide position 39373. The glycine at codon 13125 is replaced by arginine, an amino acid with dissimilar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Sudden cardiac arrest Uncertain:1
Mar 15, 2019
Center for Advanced Laboratory Medicine, UC San Diego Health, University of California San Diego
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.99
BayesDel_addAF
Uncertain
0.040
T
BayesDel_noAF
Uncertain
0.0
CADD
Benign
22
DANN
Benign
0.97
Eigen
Pathogenic
0.92
Eigen_PC
Pathogenic
0.88
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.96
D;D;D;.;D;D;D
M_CAP
Benign
0.022
T
MetaRNN
Uncertain
0.58
D;D;D;D;D;D;D
MetaSVM
Uncertain
-0.089
T
MutationAssessor
Uncertain
2.6
.;.;.;M;.;.;M
PhyloP100
7.9
PrimateAI
Pathogenic
0.85
D
PROVEAN
Pathogenic
-6.2
D;D;.;.;D;D;.
REVEL
Uncertain
0.57
Sift
Uncertain
0.0010
D;D;.;.;D;D;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.63
MutPred
0.71
.;.;.;Gain of MoRF binding (P = 0.057);.;.;Gain of MoRF binding (P = 0.057);
MVP
0.65
MPC
0.51
ClinPred
0.77
D
GERP RS
5.4
Mutation Taster
=75/25
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

Publications

Other links and lift over

dbSNP: rs757537780; hg19: chr2-179446427; API