17-8234539-G-C

Variant names:

• chr17-8234539-G-C
• rs374985738
• NM_025099.6:c.1734C>G

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_025099.6(CTC1):​c.1734C>G​(p.Ala578Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000353 in 1,416,944 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. A578A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000035 (0 hom.)
• Consequence: CTC1 NM_025099.6 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.0860
• 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

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.88).
• BP7: Synonymous conserved (PhyloP=0.086 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CTC1	NM_025099.6	c.1734C>G	p.Ala578Ala	synonymous_variant	Exon 10 of 23	ENST00000651323.1	NP_079375.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CTC1	ENST00000651323.1	c.1734C>G	p.Ala578Ala	synonymous_variant	Exon 10 of 23		NM_025099.6	ENSP00000498499.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000353 AC: 5 AN: 1416944 Hom.: 0 Cov.: 34 AF XY: 0.00000285 AC XY: 2 AN XY: 700686

African (AFR) AF: 0.00 AC: 0 AN: 32570

American (AMR) AF: 0.00 AC: 0 AN: 37186

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25316

East Asian (EAS) AF: 0.00 AC: 0 AN: 37330

South Asian (SAS) AF: 0.00 AC: 0 AN: 81006

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 50640

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5722

European-Non Finnish (NFE) AF: 0.00000368 AC: 4 AN: 1088416

Other (OTH) AF: 0.0000170 AC: 1 AN: 58758

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.88
CADD	Benign	2.5
DANN	Benign	0.38
PhyloP100		0.086

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: rs374985738; hg19: chr17-8137857;