chr17-8230562-C-A

Position:

chr17-8230562-C-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_025099.6(CTC1):c.2758+1G>T variant causes a splice donor, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000186 in 1,614,040 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

CTC1
NM_025099.6 splice_donor, intron

Scores

Splicing: ADA: 0.9999

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 2.50

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:

CTC1 (HGNC:):

CTC1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 9.1, offset of 26, new splice context is: aagGTatga. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 17-8230562-C-A is Pathogenic according to our data. Variant chr17-8230562-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 529185.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-8230562-C-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CTC1	NM_025099.6 linkuse as main transcript	c.2758+1G>T		splice_donor_variant, intron_variant		ENST00000651323.1	NP_079375.3	Q2NKJ3-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CTC1	ENST00000651323.1 linkuse as main transcript	c.2758+1G>T		splice_donor_variant, intron_variant			NM_025099.6	ENSP00000498499.1		Q2NKJ3-1

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152132

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000196

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

GnomAD3 exomes

AF:

0.0000200

AC:

AN:

249566

Hom.:

AF XY:

0.0000222

AC XY:

AN XY:

135402

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000145

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS 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:

0.0000178

AC:

AN:

1461790

Hom.:

Cov.:

AF XY:

0.0000220

AC XY:

AN XY:

727202

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000380

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:

0.00000719

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152250

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74434

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000196

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ExAC

AF:

0.00000827

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Dyskeratosis congenita

Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 11, 2023	This sequence change affects a donor splice site in intron 16 of the CTC1 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in CTC1 are known to be pathogenic (PMID: 22267198, 22387016). This variant is present in population databases (rs200609323, gnomAD 0.01%). Disruption of this splice site has been observed in individual(s) with cerebral microangiopathy with calcifications and cysts (PMID: 25197929). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 529185). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
Likely pathogenic, criteria provided, single submitter	curation	Sema4, Sema4	Dec 08, 2020	- -

Cerebroretinal microangiopathy with calcifications and cysts 1

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 31, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.45

BayesDel_noAF

Uncertain

0.11

CADD

Pathogenic

DANN

Uncertain

0.98

Eigen

Pathogenic

0.94

Eigen_PC

Pathogenic

0.75

FATHMM_MKL

Pathogenic

0.98

GERP RS

5.7

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.94

SpliceAI score (max)

0.98

Details are displayed if max score is > 0.2

DS_DG_spliceai

0.44

Position offset: -25

DS_DL_spliceai

0.98

Position offset: 1

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