rs373905859
Variant summary
Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PP3PP5_Very_Strong
The NM_025099.6(CTC1):c.2518C>T(p.Arg840Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000347 in 1,613,058 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R840Q) has been classified as Uncertain significance.
Frequency
Consequence
NM_025099.6 missense
Scores
Clinical Significance
Conservation
Publications
- cerebroretinal microangiopathy with calcifications and cysts 1Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia, Ambry Genetics, G2P
- dyskeratosis congenitaInheritance: AR, AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Orphanet
- Coats plus syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Likely_pathogenic. The variant received 9 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152222Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000804 AC: 2AN: 248778 AF XY: 0.00000741 show subpopulations
GnomAD4 exome AF: 0.0000370 AC: 54AN: 1460836Hom.: 0 Cov.: 32 AF XY: 0.0000193 AC XY: 14AN XY: 726634 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152222Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74362 show subpopulations
ClinVar
Submissions by phenotype
Cerebroretinal microangiopathy with calcifications and cysts 1 Pathogenic:2Uncertain:1
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not provided Pathogenic:1
Published functional studies demonstrate a damaging effect of genome instability (Wang et al., 2018); Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Identified in siblings with Coats plus syndrome who harbored a missense variant on the opposite allele (in trans) (Anderson et al., 2012); This variant is associated with the following publications: (PMID: 22267198, 27239262, 29481669, 29228254, 24115768, 23869908) -
Dyskeratosis congenita Pathogenic:1
This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 840 of the CTC1 protein (p.Arg840Trp). This variant is present in population databases (rs373905859, gnomAD 0.007%). This missense change has been observed in individual(s) with cerebroretinal microangiopathy with calcifications and cysts type 1 (PMID: 22267198). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 30999). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt CTC1 protein function with a negative predictive value of 80%. Experimental studies have shown that this missense change affects CTC1 function (PMID: 23869908, 24115768, 29228254, 29481669). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at