rs137852841

chr7-45064493-C-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_031443.4(CCM2):c.319C>T(p.Gln107Ter) variant causes a stop gained 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. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CCM2 NM_031443.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 2.56

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]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 7-45064493-C-T is Pathogenic according to our data. Variant chr7-45064493-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 2681.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr7-45064493-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CCM2	NM_031443.4	c.319C>T	p.Gln107Ter	stop_gained	4/10	ENST00000258781.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CCM2	ENST00000258781.11	c.319C>T	p.Gln107Ter	stop_gained	4/10	1	NM_031443.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cerebral cavernous malformation 2 Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jun 08, 2021	This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Gln107*) in the CCM2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CCM2 are known to be pathogenic (PMID: 18300272, 24689081). For these reasons, this variant has been classified as Pathogenic. This variant has been observed in individual(s) with cerebral cavernous malformations (PMID: 14624391). ClinVar contains an entry for this variant (Variation ID: 2681). -
Pathogenic, no assertion criteria provided	literature only	OMIM	Dec 01, 2003	- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Jul 07, 2021

Not observed at significant frequency in large population cohorts (Lek et al., 2016); Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 27535533, 14624391, 27722904, 27423615, 25525159) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.58
Cadd	Pathogenic	38
Dann	Uncertain	1.0
Eigen	Pathogenic	0.76
Eigen_PC	Uncertain	0.57
FATHMM_MKL	Uncertain	0.89	D
MutationTaster	Benign	1.0	A;A;A;A;A;A
Vest4		0.86
GERP RS		3.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs137852841; hg19: chr7-45104092; COSMIC: COSV51847794; COSMIC: COSV51847794;