rs137852841

Variant names:

• chr7-45064493-C-T
• rs137852841
• NM_031443.4:c.319C>T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_031443.4(CCM2):​c.319C>T​(p.Gln107*) 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
• Publications: 3 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: Pathogenic. The variant received 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 VariationId is 2681.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.319C>T	p.Gln107*	stop_gained	Exon 4 of 10	ENST00000258781.11	NP_113631.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CCM2	ENST00000258781.11	c.319C>T	p.Gln107*	stop_gained	Exon 4 of 10	1	NM_031443.4	ENSP00000258781.7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cerebral cavernous malformation 2 Pathogenic:2

Jun 08, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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). 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). -

Dec 01, 2003

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

not provided Pathogenic:1

Jul 07, 2021

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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
PhyloP100		2.6
Vest4		0.86
GERP RS		3.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=0/200	disease causing (ClinVar)

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

Other links and lift over

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