Genetic Variant CC2D2A:p.Arg1284Cys (chr4-15580046-C-T) – ACMG Classification: Pathogenic (16 pts)

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM2PM5PP3_StrongPP5_Very_Strong

The NM_001378615.1(CC2D2A):c.3850C>T(p.Arg1284Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000223 in 1,613,816 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1284H) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

CC2D2A
NM_001378615.1 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 4.76

Publications

11 publications found

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 Gene-Disease associations (from GenCC):

ciliopathy
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
Joubert syndrome 9
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, G2P
retinitis pigmentosa 93
Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
COACH syndrome 1
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
Joubert syndrome with oculorenal defect
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
Meckel syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

CC2D2A links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr4-15580047-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 987848.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.951

PP5

Variant 4-15580046-C-T is Pathogenic according to our data. Variant chr4-15580046-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 217597.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001378615.1. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
CC2D2A	NM_001378615.1	MANE Select	c.3850C>T	p.Arg1284Cys	missense	Exon 30 of 37	NP_001365544.1
CC2D2A	NM_001080522.2		c.3850C>T	p.Arg1284Cys	missense	Exon 31 of 38	NP_001073991.2
CC2D2A	NM_001378617.1		c.3703C>T	p.Arg1235Cys	missense	Exon 28 of 35	NP_001365546.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
CC2D2A	ENST00000424120.6	TSL:5 MANE Select	c.3850C>T	p.Arg1284Cys	missense	Exon 30 of 37	ENSP00000403465.1
CC2D2A	ENST00000503292.6	TSL:1	c.3850C>T	p.Arg1284Cys	missense	Exon 31 of 38	ENSP00000421809.1
CC2D2A	ENST00000634028.2	TSL:1	n.3703C>T		non_coding_transcript_exon	Exon 27 of 34	ENSP00000488669.2

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152200

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000401

AC:

AN:

249096

AF XY:

0.00000740

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000886

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000226

AC:

AN:

1461616

Hom.:

Cov.:

AF XY:

0.0000234

AC XY:

AN XY:

727092

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26130

East Asian (EAS)

AF:

0.00

AC:

AN:

39682

South Asian (SAS)

AF:

0.00

AC:

AN:

86254

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53402

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.0000297

AC:

AN:

1111814

Other (OTH)

AF:

0.00

AC:

AN:

60368

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.469

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152200

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74370

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41440

American (AMR)

AF:

0.00

AC:

AN:

15282

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5194

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10616

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000441

AC:

AN:

68046

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.458

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000457

Hom.:

Bravo

AF:

0.0000189

ExAC

AF:

0.00000828

AC:

Asia WGS

AF:

0.00115

AC:

AN:

3478

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Joubert syndrome 9

Pathogenic:2

Mar 17, 2024

Genomic Medicine Center of Excellence, King Faisal Specialist Hospital and Research Centre

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:research

Feb 23, 2015

UW Hindbrain Malformation Research Program, University of Washington

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:research

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

Pathogenic:1

Apr 12, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

not provided

Pathogenic:1

Mar 14, 2025

GeneDx

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 31589614, 31130284, 34645488, 31964843, 27894351, 38666931, 38984718, 22241855)

Meckel syndrome, type 6

Pathogenic:1

Pathology and Clinical Laboratory Medicine, King Fahad Medical City

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Meckel-Gruber syndrome;C0431399:Joubert syndrome

Pathogenic:1

Dec 24, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 1284 of the CC2D2A protein (p.Arg1284Cys). This variant is present in population databases (rs779823379, gnomAD 0.002%). This missense change has been observed in individual(s) with Joubert syndrome and related disorders (PMID: 22241855, 26092869, 27894351, 34645488). ClinVar contains an entry for this variant (Variation ID: 217597). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt CC2D2A protein function with a positive predictive value of 95%. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This variant disrupts the p.Arg1284 amino acid residue in CC2D2A. Other variant(s) that disrupt this residue have been observed in individuals with CC2D2A-related conditions (PMID: 22241855), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic.

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.46

BayesDel_addAF

Pathogenic

0.50

BayesDel_noAF

Pathogenic

0.49

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.81

Eigen

Uncertain

0.62

Eigen_PC

Uncertain

0.50

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.96

M_CAP

Pathogenic

0.35

MetaRNN

Pathogenic

0.95

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

3.4

PhyloP100

4.8

PrimateAI

Uncertain

0.56

PROVEAN

Pathogenic

-6.8

REVEL

Pathogenic

0.88

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.97

MutPred

0.72

Loss of ubiquitination at K1280 (P = 0.0949)

MVP

0.89

MPC

0.34

ClinPred

0.98

GERP RS

5.2

PromoterAI

-0.024

Neutral

(source)

Varity_R

0.70

gMVP

0.95

Mutation Taster

=2/98

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over