17-8234781-G-T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_025099.6(CTC1):​c.1585C>A​(p.Leu529Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000196 in 1,604,366 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L529F) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00012 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00020 ( 0 hom. )

Consequence

CTC1
NM_025099.6 missense

Scores

4
15

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 1.14

Publications

0 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_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.26008934).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CTC1NM_025099.6 linkc.1585C>A p.Leu529Ile missense_variant Exon 9 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.1585C>A p.Leu529Ile missense_variant Exon 9 of 23 NM_025099.6 ENSP00000498499.1 Q2NKJ3-1

Frequencies

GnomAD3 genomes
AF:
0.000125
AC:
19
AN:
152142
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:
0.000250
Gnomad OTH
AF:
0.000479
GnomAD2 exomes
AF:
0.000108
AC:
26
AN:
241848
AF XY:
0.000107
show subpopulations
Gnomad AFR exome
AF:
0.0000650
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:
0.000200
Gnomad OTH exome
AF:
0.000172
GnomAD4 exome
AF:
0.000203
AC:
295
AN:
1452224
Hom.:
0
Cov.:
34
AF XY:
0.000198
AC XY:
143
AN XY:
721672
show subpopulations
African (AFR)
AF:
0.0000602
AC:
2
AN:
33246
American (AMR)
AF:
0.0000230
AC:
1
AN:
43464
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25388
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39570
South Asian (SAS)
AF:
0.0000823
AC:
7
AN:
85082
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53154
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5728
European-Non Finnish (NFE)
AF:
0.000254
AC:
281
AN:
1106716
Other (OTH)
AF:
0.0000668
AC:
4
AN:
59876
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.470
Heterozygous variant carriers
0
18
35
53
70
88
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.000125
AC:
19
AN:
152142
Hom.:
0
Cov.:
32
AF XY:
0.000121
AC XY:
9
AN XY:
74320
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41422
American (AMR)
AF:
0.00
AC:
0
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000250
AC:
17
AN:
68016
Other (OTH)
AF:
0.000479
AC:
1
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.522
Heterozygous variant carriers
0
1
2
4
5
6
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:
0.000164
Hom.:
0
Bravo
AF:
0.000159
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.00
AC:
0
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000120
AC:
1
ExAC
AF:
0.0000744
AC:
9

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Cerebroretinal microangiopathy with calcifications and cysts 1 Uncertain:2
Jul 15, 2021
Genome-Nilou Lab
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 16, 2018
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -

not provided Uncertain:2
Jun 30, 2021
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 27535533) -

Jan 01, 2025
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

CTC1: PM2, BP4 -

Inborn genetic diseases Uncertain:1
Sep 29, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1585C>A (p.L529I) alteration is located in exon 9 (coding exon 9) of the CTC1 gene. This alteration results from a C to A substitution at nucleotide position 1585, causing the leucine (L) at amino acid position 529 to be replaced by an isoleucine (I). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

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

This sequence change replaces leucine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 529 of the CTC1 protein (p.Leu529Ile). This variant is present in population databases (rs201560353, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with CTC1-related conditions. ClinVar contains an entry for this variant (Variation ID: 577242). 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%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.15
BayesDel_addAF
Benign
-0.21
T
BayesDel_noAF
Benign
-0.25
CADD
Benign
22
DANN
Benign
0.94
DEOGEN2
Benign
0.34
T
Eigen
Benign
-0.17
Eigen_PC
Benign
-0.17
FATHMM_MKL
Uncertain
0.90
D
LIST_S2
Benign
0.72
T
M_CAP
Benign
0.047
D
MetaRNN
Benign
0.26
T
MetaSVM
Uncertain
-0.26
T
MutationAssessor
Uncertain
2.6
M
PhyloP100
1.1
PrimateAI
Benign
0.47
T
PROVEAN
Benign
-0.68
N
REVEL
Benign
0.22
Sift
Benign
0.25
T
Sift4G
Uncertain
0.044
D
Polyphen
0.87
P
Vest4
0.44
MVP
0.56
MPC
0.37
ClinPred
0.084
T
GERP RS
2.0
Varity_R
0.057
gMVP
0.38
Mutation Taster
=92/8
polymorphism

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: rs201560353; hg19: chr17-8138099; API