rs373905859

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PP3PP5_Very_Strong

The NM_025099.6(CTC1):​c.2518C>T​(p.Arg840Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000347 in 1,613,058 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R840Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000037 ( 0 hom. )

Consequence

CTC1
NM_025099.6 missense

Scores

1
11
7

Clinical Significance

Likely pathogenic criteria provided, multiple submitters, no conflicts P:4U:1

Conservation

PhyloP100: 3.33

Publications

9 publications found
Variant links:
Genes affected
CTC1 (HGNC:26169): (CST telomere replication complex component 1) This gene encodes a component of the CST complex. This complex plays an essential role in protecting telomeres from degradation. This protein also forms a heterodimer with the CST complex subunit STN1 to form the enzyme alpha accessory factor. This enzyme regulates DNA replication. Mutations in this gene are the cause of cerebroretinal microangiopathy with calcifications and cysts. Alternate splicing results in both coding and non-coding variants. [provided by RefSeq, Mar 2012]
CTC1 Gene-Disease associations (from GenCC):
  • cerebroretinal microangiopathy with calcifications and cysts 1
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia, Ambry Genetics, G2P
  • dyskeratosis congenita
    Inheritance: AR, AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Orphanet
  • Coats plus syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.783
PP5
Variant 17-8231427-G-A is Pathogenic according to our data. Variant chr17-8231427-G-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 30999.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CTC1NM_025099.6 linkc.2518C>T p.Arg840Trp missense_variant Exon 15 of 23 ENST00000651323.1 NP_079375.3 Q2NKJ3-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CTC1ENST00000651323.1 linkc.2518C>T p.Arg840Trp missense_variant Exon 15 of 23 NM_025099.6 ENSP00000498499.1 Q2NKJ3-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152222
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
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
GnomAD2 exomes
AF:
0.00000804
AC:
2
AN:
248778
AF XY:
0.00000741
show subpopulations
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:
0.00
Gnomad NFE exome
AF:
0.0000177
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000370
AC:
54
AN:
1460836
Hom.:
0
Cov.:
32
AF XY:
0.0000193
AC XY:
14
AN XY:
726634
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33452
American (AMR)
AF:
0.0000448
AC:
2
AN:
44600
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26122
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39666
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86146
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53404
Middle Eastern (MID)
AF:
0.000179
AC:
1
AN:
5596
European-Non Finnish (NFE)
AF:
0.0000414
AC:
46
AN:
1111510
Other (OTH)
AF:
0.0000829
AC:
5
AN:
60340
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.483
Heterozygous variant carriers
0
3
5
8
10
13
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152222
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74362
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41452
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68044
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.625
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000268
Hom.:
0
Bravo
AF:
0.0000264
ESP6500AA
AF:
0.000241
AC:
1
ESP6500EA
AF:
0.000119
AC:
1
ExAC
AF:
0.00000826
AC:
1
EpiCase
AF:
0.0000545
EpiControl
AF:
0.0000593

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:4Uncertain:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Cerebroretinal microangiopathy with calcifications and cysts 1 Pathogenic:2Uncertain:1
Jul 15, 2021
Genome-Nilou Lab
Significance:Uncertain significance
Review Status:flagged submission
Collection Method:clinical testing

- -

Jan 22, 2012
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

May 05, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Pathogenic:1
Jan 07, 2021
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Published functional studies demonstrate a damaging effect of genome instability (Wang et al., 2018); Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Identified in siblings with Coats plus syndrome who harbored a missense variant on the opposite allele (in trans) (Anderson et al., 2012); This variant is associated with the following publications: (PMID: 22267198, 27239262, 29481669, 29228254, 24115768, 23869908) -

Dyskeratosis congenita Pathogenic:1
Jun 22, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 840 of the CTC1 protein (p.Arg840Trp). This variant is present in population databases (rs373905859, gnomAD 0.007%). This missense change has been observed in individual(s) with cerebroretinal microangiopathy with calcifications and cysts type 1 (PMID: 22267198). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 30999). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt CTC1 protein function with a negative predictive value of 80%. Experimental studies have shown that this missense change affects CTC1 function (PMID: 23869908, 24115768, 29228254, 29481669). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.083
BayesDel_addAF
Uncertain
0.018
T
BayesDel_noAF
Uncertain
-0.030
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.60
D
Eigen
Uncertain
0.26
Eigen_PC
Uncertain
0.28
FATHMM_MKL
Uncertain
0.82
D
LIST_S2
Benign
0.82
T
M_CAP
Benign
0.023
T
MetaRNN
Pathogenic
0.78
D
MetaSVM
Benign
-0.36
T
MutationAssessor
Benign
0.90
L
PhyloP100
3.3
PrimateAI
Benign
0.21
T
PROVEAN
Uncertain
-3.2
D
REVEL
Uncertain
0.39
Sift
Uncertain
0.017
D
Sift4G
Uncertain
0.0080
D
Polyphen
0.99
D
Vest4
0.74
MVP
0.70
MPC
0.45
ClinPred
0.74
D
GERP RS
5.9
Varity_R
0.10
gMVP
0.36
Mutation Taster
=32/68
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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: rs373905859; hg19: chr17-8134745; API