rs797044623

Variant names:

• chr7-45000368-GC-TT
• rs797044623
• NM_031443.4:c.30+5_30+6delGCinsTT

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PP5_Very_Strong

The NM_031443.4(CCM2):​c.30+5_30+6delGCinsTT 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. It is difficult to determine the true allele frequency of this variant because it is of type MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 24)
• Consequence: CCM2 NM_031443.4 splice_region, intron
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6 O:1
• Conservation: PhyloP100: 0.963
• Publications: 1 publications found

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]

CCM2 Gene-Disease associations (from GenCC):

• cerebral cavernous malformation 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• famililal cerebral cavernous malformations

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PP5: Variant 7-45000368-GC-TT is Pathogenic according to our data. Variant chr7-45000368-GC-TT is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 193463.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
CCM2	NM_031443.4	c.30+5_30+6delGCinsTT		splice_region_variant, intron_variant	Intron 1 of 9	ENST00000258781.11	NP_113631.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CCM2	ENST00000258781.11	c.30+5_30+6delGCinsTT		splice_region_variant, intron_variant	Intron 1 of 9	1	NM_031443.4	ENSP00000258781.7

Frequencies

GnomAD3 genomes Cov.: 24

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 24

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:3

Jan 05, 2024

Athena Diagnostics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The frequency of this variant in the general population is consistent with pathogenicity (Genome Aggregation Database (gnomAD), Cambridge, MA (URL: http://gnomad.broadinstitute.org)). This variant has been identified in multiple unrelated individuals with clinical features associated with this gene. Assessment of experimental evidence suggests this variant results in abnormal RNA splicing (PMID: 21543988, 23595507). -

Mar 11, 2015

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 05, 2025

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Non-canonical splice site variant demonstrated to result in loss-of-function (PMID: 21543988, 23595507); This variant is associated with the following publications: (PMID: 23595507, 33729445, 21543988, RicciC2021[Article]) -

Cerebral cavernous malformation 2 Pathogenic:2 Other:1

Jul 01, 2011

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

-

GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Jan 20, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change falls in intron 1 of the CCM2 gene. It does not directly change the encoded amino acid sequence of the CCM2 protein. RNA analysis indicates that this variant induces altered splicing and may result in an absent or altered protein product. Information on the frequency of this variant in the gnomAD database is not available, as this variant may be reported differently in the database. This variant has been observed in individual(s) with clinical features of cerebral cavernous malformations (PMID: 21543988, 23595507; internal data). ClinVar contains an entry for this variant (Variation ID: 193463). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant results in activation of a cryptic splice site, and produces a non-functional protein and/or introduces a premature termination codon (PMID: 21543988). For these reasons, this variant has been classified as Pathogenic. -

CCM2-related disorder Pathogenic:1

Jul 05, 2024

PreventionGenetics, part of Exact Sciences

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The CCM2 c.30+5_30+6delinsTT variant is predicted to result in an in-frame deletion and insertion. This variant has been reported as a founder variant in individuals of Ashkenazi Jewish ancestry and functional studies have shown that it affects splicing (Gallione et al. 2011. PubMed ID: 21543988). This variant has not been reported in a large population database, indicating this variant is rare. This variant has been interpreted as pathogenic by multiple submitters in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/193463). Based on this evidence, we interpret this variant as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.96
Mutation Taster		=4/96	disease causing

Splicing

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

Other links and lift over

dbSNP: rs797044623; hg19: chr7-45039967;