17-8238389-C-G

Variant names:

• chr17-8238389-C-G
• rs6503093
• NM_025099.6:c.435+3G>C

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_025099.6(CTC1):​c.435+3G>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 31)
• Consequence: CTC1 NM_025099.6 splice_region, intron
• Scores: Splicing: ADA: 0.05831
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.0800
• Publications: 10 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 -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.81).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_025099.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CTC1	NM_025099.6	MANE Select	c.435+3G>C		splice_region intron	N/A	NP_079375.3
	CTC1	NM_001411067.1		c.435+3G>C		splice_region intron	N/A	NP_001397996.1
	CTC1	NR_046431.2		n.455+3G>C		splice_region intron	N/A

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CTC1	ENST00000651323.1	MANE Select	c.435+3G>C		splice_region intron	N/A	ENSP00000498499.1
	CTC1	ENST00000584842.1	TSL:3	n.381G>C		non_coding_transcript_exon	Exon 2 of 2
	CTC1	ENST00000581729.2	TSL:3	c.435+3G>C		splice_region intron	N/A	ENSP00000462720.2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.81
CADD	Benign	14
PhyloP100		-0.080

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.058
dbscSNV1_RF	Benign	0.20
SpliceAI score (max)		0.56		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.56		Position offset: 3

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs6503093; hg19: chr17-8141707;