dbSNP rs370354906: CTC1:p.Pro754Ala (chr17-8232028-G-C) – ACMG Classification: Likely_benign (-2 pts)

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_025099.6(CTC1):c.2260C>G(p.Pro754Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000882 in 1,587,338 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000049 ( 0 hom. )

Consequence

CTC1
NM_025099.6 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: -0.543

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.044857085).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CTC1	NM_025099.6 link	c.2260C>G	p.Pro754Ala	missense_variant	Exon 13 of 23	ENST00000651323.1	NP_079375.3	Q2NKJ3-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CTC1	ENST00000651323.1 link	c.2260C>G	p.Pro754Ala	missense_variant	Exon 13 of 23		NM_025099.6	ENSP00000498499.1		Q2NKJ3-1

Frequencies

GnomAD3 genomes

AF:

0.0000460

AC:

AN:

152166

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000169

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000488

AC:

AN:

1435056

Hom.:

Cov.:

AF XY:

0.00000420

AC XY:

AN XY:

713468

show subpopulations

Gnomad4 AFR exome

AF:

0.000188

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:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000460

AC:

AN:

152282

Hom.:

Cov.:

AF XY:

0.0000806

AC XY:

AN XY:

74466

show subpopulations

Gnomad4 AFR

AF:

0.000168

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:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.0000227

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Dyskeratosis congenita

Uncertain:2

Oct 13, 2021

Sema4, Sema4

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: curation

- -

Sep 16, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces proline, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 754 of the CTC1 protein (p.Pro754Ala). This variant is present in population databases (rs370354906, gnomAD 0.03%). 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: 568849). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt CTC1 protein function with a negative 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. -

Cerebroretinal microangiopathy with calcifications and cysts 1

Uncertain:1

Mar 07, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Inborn genetic diseases

Uncertain:1

Sep 10, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.2260C>G (p.P754A) alteration is located in exon 13 (coding exon 13) of the CTC1 gene. This alteration results from a C to G substitution at nucleotide position 2260, causing the proline (P) at amino acid position 754 to be replaced by an alanine (A). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.062

BayesDel_addAF

Benign

-0.13

BayesDel_noAF

Benign

-0.42

CADD

Benign

3.2

DANN

Benign

0.30

DEOGEN2

Benign

0.33

Eigen

Benign

-1.6

Eigen_PC

Benign

-1.7

FATHMM_MKL

Benign

0.037

LIST_S2

Benign

0.59

M_CAP

Benign

0.027

MetaRNN

Benign

0.045

MetaSVM

Benign

-0.81

MutationAssessor

Benign

1.4

PrimateAI

Benign

0.23

PROVEAN

Benign

-1.1

REVEL

Benign

0.19

Sift

Benign

0.84

Sift4G

Benign

0.56

Polyphen

0.058

Vest4

0.10

MutPred

0.12

Loss of disorder (P = 0.0807);

MVP

0.17

MPC

0.12

ClinPred

0.053

GERP RS

-6.9

RBP_binding_hub_radar

0.97

RBP_regulation_power_radar

2.1

Varity_R

0.11

gMVP

0.099

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.030

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over