7-45000364-G-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_031443.4(CCM2):​c.30+1G>A variant causes a splice donor, 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 pathogenic outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: not found (cov: 24)
Exomes 𝑓: 0.0 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

CCM2
NM_031443.4 splice_donor, intron

Scores

1
1
5
Splicing: ADA: 0.00007757
2

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 1.58
Variant links:
Genes affected
CCM2 (HGNC:21708): (CCM2 scaffold protein) This gene encodes a scaffold protein that functions in the stress-activated p38 Mitogen-activated protein kinase (MAPK) signaling cascade. The protein interacts with SMAD specific E3 ubiquitin protein ligase 1 (also known as SMURF1) via a phosphotyrosine binding domain to promote RhoA degradation. The protein is required for normal cytoskeletal structure, cell-cell interactions, and lumen formation in endothelial cells. Mutations in this gene result in cerebral cavernous malformations. Multiple transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Nov 2009]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 7-45000364-G-A is Pathogenic according to our data. Variant chr7-45000364-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 590655.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CCM2NM_031443.4 linkc.30+1G>A splice_donor_variant, intron_variant Intron 1 of 9 ENST00000258781.11 NP_113631.1 Q9BSQ5-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CCM2ENST00000258781.11 linkc.30+1G>A splice_donor_variant, intron_variant Intron 1 of 9 1 NM_031443.4 ENSP00000258781.7 Q9BSQ5-1

Frequencies

GnomAD3 genomes
Cov.:
24
GnomAD4 exome
Data not reliable, filtered out with message: AC0
AF:
0.00
AC:
0
AN:
1156554
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
558626
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:
0.00
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
24

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:3
Feb 15, 2020
PreventionGenetics, part of Exact Sciences
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Mar 19, 2021
Athena Diagnostics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant is expected to severely impact normal RNA splicing, and consequently, protein structure and/or function. This variant has not been reported in large, multi-ethnic general populations (http://gnomad.broadinstitute.org). This variant has been identified in at least one individual with clinical features associated with this gene. -

Apr 13, 2023
GeneDx
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Canonical splice site variant in a gene for which loss-of-function is a known mechanism of disease; Not observed in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 19088124, 15122722, 14624391, 17160895, 34426522, 18300272) -

Cerebral cavernous malformation 2 Pathogenic:2
Aug 21, 2024
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The CCM2 c.30+1G>A variant (rs1562848479, ClinVar Variation ID: 590655) is reported in the literature in individuals affected with cerebral cavernous malformations (Stahl 2008, Verlaan 2004). This variant is absent from the Genome Aggregation Database (v2.1.1), indicating it is not a common polymorphism. This variant disrupts the canonical splice donor site of intron 1, which is likely to negatively impact gene function. In vitro functional analysis by immunohistochemistry shows localized loss of CCM2 expression in the cavernous endothelial cells (Pagenstecher 2009). Based on available information, this variant is considered to be pathogenic. References: Pagenstecher A et al. A two-hit mechanism causes cerebral cavernous malformations: complete inactivation of CCM1, CCM2 or CCM3 in affected endothelial cells. Hum Mol Genet. 2009 Mar 1;18(5):911-8. PMID: 19088124. Stahl S et al. Novel CCM1, CCM2, and CCM3 mutations in patients with cerebral cavernous malformations: in-frame deletion in CCM2 prevents formation of a CCM1/CCM2/CCM3 protein complex. Hum Mutat. 2008 May;29(5):709-17. PMID: 18300272. Verlaan DJ et al. CCM2 mutations account for 13% of cases in a large collection of kindreds with hereditary cavernous malformations. Ann Neurol. 2004 May;55(5):757-8. PMID: 15122722. -

Dec 31, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change affects a donor splice site in intron 1 of the CCM2 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in CCM2 are known to be pathogenic (PMID: 18300272, 24689081). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with cerebral cavernous malformations (PMID: 15122722, 19088124). This variant is also known as IVS+1G>A. ClinVar contains an entry for this variant (Variation ID: 590655). Algorithms developed to predict the effect of variants on gene product structure and function are not available or were not evaluated for this variant. Experimental studies have shown that disruption of this splice site affects CCM2 function (PMID: 19088124). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.62
D
BayesDel_noAF
Benign
-0.68
CADD
Pathogenic
26
DANN
Benign
0.91
Eigen
Uncertain
0.37
Eigen_PC
Benign
-0.0049
FATHMM_MKL
Benign
0.11
N
GERP RS
1.4
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.2

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.000078
dbscSNV1_RF
Benign
0.010
SpliceAI score (max)
0.99
Details are displayed if max score is > 0.2
DS_DG_spliceai
0.46
Position offset: 31
DS_DL_spliceai
0.99
Position offset: -1

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.

Other links and lift over

dbSNP: rs1562848479; hg19: chr7-45039963; API