Genetic Variant CC2D2A:p.Arg132* (chr4-15502879-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.394C>T(p.Arg132*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000149 in 1,611,658 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000072 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

CC2D2A
NM_001378615.1 stop_gained

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 1.52

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 4-15502879-C-T is Pathogenic according to our data. Variant chr4-15502879-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 126242.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
CC2D2A	NM_001378615.1 link	c.394C>T	p.Arg132*	stop_gained	Exon 6 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.394C>T	p.Arg132*	stop_gained	Exon 6 of 37	5	NM_001378615.1	ENSP00000403465.1		Q9P2K1-4

Frequencies

GnomAD3 genomes

AF:

0.0000723

AC:

AN:

152104

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000266

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:

0.0000285

AC:

AN:

245614

Hom.:

AF XY:

0.0000225

AC XY:

AN XY:

133172

show subpopulations

Gnomad AFR exome

AF:

0.000464

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000891

AC:

AN:

1459436

Hom.:

Cov.:

AF XY:

0.00000689

AC XY:

AN XY:

725776

show subpopulations

Gnomad4 AFR exome

AF:

0.000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000234

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000723

AC:

AN:

152222

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74404

show subpopulations

Gnomad4 AFR

AF:

0.000265

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

Alfa

AF:

0.0000657

Hom.:

Bravo

AF:

0.0000680

ESP6500AA

AF:

0.000535

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000497

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:2

Apr 18, 2023

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 a significant frequency in large population cohorts (gnomAD); Has not been previously published as pathogenic or benign in association with a CC2D2A-related disorder to our knowledge; This variant is associated with the following publications: (PMID: 31589614) -

Mar 21, 2017

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

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

Pathogenic:1

Aug 11, 2024

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.Arg132*) 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 (rs377177061, gnomAD 0.04%). This variant has not been reported in the literature in individuals affected with CC2D2A-related conditions. ClinVar contains an entry for this variant (Variation ID: 126242). For these reasons, this variant has been classified as Pathogenic. -

Joubert syndrome 9;C2676790:Meckel syndrome, type 6;C5436837:COACH syndrome 2;C5676970:Retinitis pigmentosa 93

Pathogenic:1

Mar 09, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Meckel-Gruber syndrome

Pathogenic:1

Dec 18, 2019

Genetic Services Laboratory, University of Chicago

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Meckel syndrome, type 6

Pathogenic:1

Jun 21, 2023

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: CC2D2A c.394C>T (p.Arg132X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 2.9e-05 in 245614 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.394C>T in individuals affected with Meckel Syndrome Type 6 and no experimental evidence demonstrating its impact on protein function have been reported. Five submitters have reported clinical-significance assessments for this variant to ClinVar after 2014, and all submitters classified the variant as pathogenic (n = 3) or likely pathogenic (n = 2). Based on the evidence outlined above, the variant was classified as pathogenic. -

Retinal dystrophy

Pathogenic:1

Sep 15, 2017

Blueprint Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Joubert syndrome 9

Pathogenic:1

Jun 13, 2024

Greenwood Genetic Center Diagnostic Laboratories, Greenwood Genetic Center

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PVS1, PM2 -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Uncertain

0.12

BayesDel_noAF

Pathogenic

0.28

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Uncertain

0.25

Eigen_PC

Benign

-0.0033

FATHMM_MKL

Benign

0.061

Vest4

0.74

GERP RS

2.9

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.050

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