dbSNP rs386833748: CC2D2A:p.Arg925* (chr4-15557451-C-T) – ACMG Classification: Pathogenic (18 pts)

Variant summary

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

The NM_001378615.1(CC2D2A):c.2773C>T(p.Arg925*) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000434 in 1,612,388 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 (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

CC2D2A
NM_001378615.1 stop_gained

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 3.96

Variant links:

Genes affected

CC2D2A (HGNC:29253): (coiled-coil and C2 domain containing 2A) This gene encodes a coiled-coil and calcium binding domain protein that appears to play a critical role in cilia formation. Mutations in this gene cause Meckel syndrome type 6, as well as Joubert syndrome type 9. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Sep 2009]

CC2D2A links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

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 4-15557451-C-T is Pathogenic according to our data. Variant chr4-15557451-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 56300.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr4-15557451-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CC2D2A	NM_001378615.1 link	c.2773C>T	p.Arg925*	stop_gained	Exon 21 of 37	ENST00000424120.6	NP_001365544.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CC2D2A	ENST00000424120.6 link	c.2773C>T	p.Arg925*	stop_gained	Exon 21 of 37	5	NM_001378615.1	ENSP00000403465.1		Q9P2K1-4

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

151954

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000242

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000122

AC:

AN:

246056

Hom.:

AF XY:

0.0000150

AC XY:

AN XY:

133586

show subpopulations

Gnomad AFR exome

AF:

0.0000660

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000898

Gnomad OTH exome

AF:

0.000168

GnomAD4 exome

AF:

0.00000411

AC:

AN:

1460434

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

726468

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.0000384

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000270

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000658

AC:

AN:

151954

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74206

show subpopulations

Gnomad4 AFR

AF:

0.0000242

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

ExAC

AF:

0.0000166

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Meckel-Gruber syndrome;C0431399:Familial aplasia of the vermis

Pathogenic:1

Jan 06, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Arg925*) in the CC2D2A gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CC2D2A are known to be pathogenic (PMID: 19777577). This variant is present in population databases (rs386833748, gnomAD 0.007%). This premature translational stop signal has been observed in individual(s) with Meckel syndrome (PMID: 19777577). ClinVar contains an entry for this variant (Variation ID: 56300). For these reasons, this variant has been classified as Pathogenic. -

not provided

Pathogenic:1

Feb 26, 2024

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 33486889, 25525159, 31964843, 19777577) -

Meckel syndrome, type 6

Pathogenic:1

Juha Muilu Group; Institute for Molecular Medicine Finland (FIMM)

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

CC2D2A-related disorder

Pathogenic:1

Dec 18, 2018

Illumina Laboratory Services, Illumina

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The CC2D2A c.2773C>T (p.Arg925Ter) variant is a stop-gained variant that is predicted to result in a premature termination of the protein. The p.Arg925Ter variant has been reported in a compound heterozygous state with a splice site variant in a fetus diagnosed at 16 weeks gestation with cystic kidneys characteristic of Meckel syndrome, bile duct proliferation of the liver, occipital meningocele of the central nervous system, and polydactyly (Mougou-Zerelli et al. 2009). Akizu et al. (2014) found this variant in a homozygous state in an individual from a consanguineous union described as having classic Joubert syndrome. An immunoblot assay in fibroblasts from this homozygous individual revealed severely reduced protein levels. Control data are unavailable for this variant, which is not found in the 1000 Genomes Project, the Exome Sequencing Project, the Exome Aggregation Consortium, or the Genome Aggregation Database. Based on the evidence and due to the potential impact of stop-gained variants, the p.Arg925Ter variant is classified as likely pathogenic CC2D2A-related disorders. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.48

BayesDel_noAF

Pathogenic

0.63

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Pathogenic

0.79

Eigen_PC

Uncertain

0.65

FATHMM_MKL

Uncertain

0.95

Vest4

0.95

GERP RS

4.7

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over