dbSNP rs1196342305: CTC1:p.Ile147LysfsTer45 (chr17-8238237-TA-T) – ACMG Classification: Pathogenic (12 pts)

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1PM2PP5_Moderate

The NM_025099.6(CTC1):c.440delT(p.Ile147LysfsTer45) variant causes a frameshift change. The variant allele was found at a frequency of 0.0000131 in 1,603,592 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)

Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

CTC1
NM_025099.6 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 5.40

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 Pathogenic. Variant got 12 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 17-8238237-TA-T is Pathogenic according to our data. Variant chr17-8238237-TA-T is described in ClinVar as [Pathogenic]. Clinvar id is 529178.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CTC1	NM_025099.6 link	c.440delT	p.Ile147LysfsTer45	frameshift_variant	Exon 4 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.440delT	p.Ile147LysfsTer45	frameshift_variant	Exon 4 of 23		NM_025099.6	ENSP00000498499.1		Q2NKJ3-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152232

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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

GnomAD4 exome

AF:

0.0000138

AC:

AN:

1451360

Hom.:

Cov.:

AF XY:

0.0000153

AC XY:

AN XY:

720556

show subpopulations

Gnomad4 AFR exome

AF:

0.00

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:

0.0000172

Gnomad4 OTH exome

AF:

0.0000167

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152232

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74372

show subpopulations

Gnomad4 AFR

AF:

0.00

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Dyskeratosis congenita

Pathogenic:1

Nov 10, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported in the literature in individuals with CTC1-related conditions. This sequence change creates a premature translational stop signal (p.Ile147Lysfs*45) in the CTC1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CTC1 are known to be pathogenic (PMID: 22267198, 22387016). This variant is not present in population databases (ExAC no frequency). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

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