rs387907080

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.775G>A​(p.Val259Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000616 in 1,461,880 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 (★★).

Frequency

Genomes: not found (cov: 29)
Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

CTC1
NM_025099.6 missense

Scores

3
11
4

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 3.56

Publications

14 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, 0.822
PP5
Variant 17-8237392-C-T is Pathogenic according to our data. Variant chr17-8237392-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 30998.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_025099.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CTC1
NM_025099.6
MANE Select
c.775G>Ap.Val259Met
missense
Exon 5 of 23NP_079375.3
CTC1
NM_001411067.1
c.775G>Ap.Val259Met
missense
Exon 5 of 21NP_001397996.1
CTC1
NR_046431.2
n.690G>A
non_coding_transcript_exon
Exon 5 of 22

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CTC1
ENST00000651323.1
MANE Select
c.775G>Ap.Val259Met
missense
Exon 5 of 23ENSP00000498499.1
CTC1
ENST00000699849.1
c.-123G>A
5_prime_UTR_premature_start_codon_gain
Exon 4 of 20ENSP00000514647.1
CTC1
ENST00000581729.2
TSL:3
c.775G>Ap.Val259Met
missense
Exon 5 of 21ENSP00000462720.2

Frequencies

GnomAD3 genomes
Cov.:
29
GnomAD2 exomes
AF:
0.00000801
AC:
2
AN:
249574
AF XY:
0.00000739
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000579
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:
0.00
GnomAD4 exome
AF:
0.00000616
AC:
9
AN:
1461880
Hom.:
0
Cov.:
31
AF XY:
0.00000413
AC XY:
3
AN XY:
727238
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000671
AC:
3
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1111998
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.453
Heterozygous variant carriers
0
1
2
2
3
4
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
Cov.:
29
Alfa
AF:
0.00
Hom.:
0
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:7
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Cerebroretinal microangiopathy with calcifications and cysts 1 Pathogenic:5
Aug 18, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Jul 15, 2021
Genome-Nilou Lab
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Apr 09, 2018
Mayo Clinic Laboratories, Mayo Clinic
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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

Jun 13, 2022
Baylor Genetics
Significance: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

Multiple published functional studies demonstrate a damaging effect of V259M, including abolished association with endogenous DNA polymerase alpha-primase, protein accumulation in the cytoplasm, excessive telomere loss, spontaneous chromosome breakage, severe chromosome fragmentation, reduced cellular proliferation, and poor cell survival under replication stress (Chen et al., 2013; Wang et al., 2018); This variant is associated with the following publications: (PMID: 31589614, 23220793, 22267198, 29111009, 29774655, 29481669, 24115768, 23869908, 18076099)

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

This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 259 of the CTC1 protein (p.Val259Met). This variant is present in population databases (rs387907080, gnomAD 0.006%). This missense change has been observed in individual(s) with Coats plus syndrome (PMID: 22267198, 29111009). 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: 30998). 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 expected to disrupt CTC1 protein function with a positive predictive value of 80%. Experimental studies have shown that this missense change affects CTC1 function (PMID: 24115768, 29481669). For these reasons, this variant has been classified as Pathogenic.

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.41
BayesDel_addAF
Pathogenic
0.19
D
BayesDel_noAF
Pathogenic
0.21
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.49
T
Eigen
Uncertain
0.42
Eigen_PC
Uncertain
0.31
FATHMM_MKL
Benign
0.59
D
LIST_S2
Benign
0.85
D
M_CAP
Benign
0.061
D
MetaRNN
Pathogenic
0.82
D
MetaSVM
Uncertain
0.76
D
MutationAssessor
Uncertain
2.5
M
PhyloP100
3.6
PrimateAI
Uncertain
0.53
T
PROVEAN
Benign
-1.2
N
REVEL
Uncertain
0.48
Sift
Uncertain
0.0030
D
Sift4G
Uncertain
0.011
D
Polyphen
1.0
D
Vest4
0.84
MutPred
0.31
Loss of sheet (P = 0.0357)
MVP
0.80
MPC
0.52
ClinPred
0.86
D
GERP RS
4.8
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.0
Varity_R
0.23
gMVP
0.53
Mutation Taster
=38/62
disease causing (ClinVar)

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: rs387907080; hg19: chr17-8140710; API