rs139845972

Variant names:

• chr17-8224949-T-C
• rs139845972
• NM_025099.6:c.*3231A>G

Variant summary

Our verdict is Benign. The variant received -14 ACMG points: 0P and 14B. BP4_Strong BP6_Moderate BS1 BS2

The NM_025099.6(CTC1):​c.*3231A>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00619 in 152,278 control chromosomes in the GnomAD database, including 11 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★).

• Frequency:
  • Genomes: 𝑓 0.0062 (11 hom., cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CTC1 NM_025099.6 3_prime_UTR
• Clinical Significance: Benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 0.537
• Publications: 0 publications found

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

ENSG00000305852 (HGNC:):

ACMG classification

Our verdict: Benign. The variant received -14 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.91).
• BP6: Variant 17-8224949-T-C is Benign according to our data. Variant chr17-8224949-T-C is described in ClinVar as [Benign]. Clinvar id is 325985.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS1: Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00619 (942/152278) while in subpopulation AFR AF = 0.0218 (907/41548). AF 95% confidence interval is 0.0207. There are 11 homozygotes in GnomAd4. There are 428 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
• BS2: High Homozygotes in GnomAd4 at 11 AR,AD gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CTC1	NM_025099.6	c.*3231A>G		3_prime_UTR_variant	Exon 23 of 23	ENST00000651323.1	NP_079375.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CTC1	ENST00000651323.1	c.*3231A>G		3_prime_UTR_variant	Exon 23 of 23		NM_025099.6	ENSP00000498499.1
ENSG00000305852	ENST00000813476.1	n.104-581T>C		intron_variant	Intron 1 of 1
ENSG00000305852	ENST00000813477.1	n.132-581T>C		intron_variant	Intron 1 of 1

Frequencies

GnomAD3 genomes AF: 0.00618 AC: 940 AN: 152160 Hom.: 11 Cov.: 32

Gnomad AFR AF: 0.0218

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00170

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00316

Gnomad NFE AF: 0.0000588

Gnomad OTH AF: 0.00191

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 36 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 22

African (AFR) AC: 0 AN: 0

American (AMR) AC: 0 AN: 0

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 2

East Asian (EAS) AC: 0 AN: 0

South Asian (SAS) AF: 0.00 AC: 0 AN: 6

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 2

Middle Eastern (MID) AC: 0 AN: 0

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 20

Other (OTH) AF: 0.00 AC: 0 AN: 6

GnomAD4 genome AF: 0.00619 AC: 942 AN: 152278 Hom.: 11 Cov.: 32 AF XY: 0.00575 AC XY: 428 AN XY: 74460

African (AFR) AF: 0.0218 AC: 907 AN: 41548

American (AMR) AF: 0.00170 AC: 26 AN: 15290

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5176

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10632

Middle Eastern (MID) AF: 0.00340 AC: 1 AN: 294

European-Non Finnish (NFE) AF: 0.0000588 AC: 4 AN: 68016

Other (OTH) AF: 0.00189 AC: 4 AN: 2112

Alfa AF: 0.00506 Hom.: 0

Bravo AF: 0.00720

Asia WGS AF: 0.000577 AC: 2 AN: 3478

ClinVar

Significance: Benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Dyskeratosis congenita Benign:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.91
CADD	Benign	3.3
DANN	Benign	0.59
PhyloP100		0.54

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

Other links and lift over

dbSNP: rs139845972; hg19: chr17-8128267;