4-15553306-G-C

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_001378615.1(CC2D2A):c.2486+1G>C variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,611,550 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

CC2D2A
NM_001378615.1 splice_donor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

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

Conservation

PhyloP100: 8.93

Publications

3 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 18 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 4-15553306-G-C is Pathogenic according to our data. Variant chr4-15553306-G-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 56299.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	Effect	Exon Rank	Protein
CC2D2A	NM_001378615.1	MANE Select	c.2486+1G>C	splice_donor intron	N/A	NP_001365544.1
CC2D2A	NM_001080522.2		c.2486+1G>C	splice_donor intron	N/A	NP_001073991.2
CC2D2A	NM_001378617.1		c.2339+1G>C	splice_donor intron	N/A	NP_001365546.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	Effect	Exon Rank	Protein
CC2D2A	ENST00000424120.6	TSL:5 MANE Select	c.2486+1G>C	splice_donor intron	N/A	ENSP00000403465.1
CC2D2A	ENST00000503292.6	TSL:1	c.2486+1G>C	splice_donor intron	N/A	ENSP00000421809.1
CC2D2A	ENST00000634028.2	TSL:1	n.2339+1G>C	splice_donor intron	N/A	ENSP00000488669.2

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152180

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

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

GnomAD2 exomes

AF:

0.00000405

AC:

AN:

246794

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000297

Gnomad ASJ exome

AF:

0.00

Gnomad EAS 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:

0.00000411

AC:

AN:

1459370

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

725842

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33348

American (AMR)

AF:

0.0000225

AC:

AN:

44376

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26102

East Asian (EAS)

AF:

0.00

AC:

AN:

39572

South Asian (SAS)

AF:

0.00

AC:

AN:

85578

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53350

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.00000270

AC:

AN:

1111000

Other (OTH)

AF:

0.0000332

AC:

AN:

60278

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

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:

0.00000657

AC:

AN:

152180

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74344

show subpopulations

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

41438

American (AMR)

AF:

0.0000654

AC:

AN:

15282

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5202

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10602

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68040

Other (OTH)

AF:

0.00

AC:

AN:

2092

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.275

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Meckel syndrome, type 6

Pathogenic:2

Nov 18, 2022

Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

ACMG classification criteria: PVS1 very strong, PS4 supporting, PM2 moderated, PM3 supporting

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

Significance:Likely pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

not provided

Pathogenic:1

Sep 23, 2024

GeneDx

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Reported previously in a fetus with features of Meckel-Gruber syndrome including polydactyly, occipital meningocele, and bile duct proliferation of liver who also harbored a second variant, phase unknown (PMID: 19777577); Canonical splice site variant predicted to result in a null allele 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: 30267408, 31589614, 25525159, 31964843, 19777577)

Meckel-Gruber syndrome;C0431399:Joubert syndrome

Pathogenic:1

Sep 26, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This sequence change affects a donor splice site in intron 20 of the CC2D2A gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in CC2D2A are known to be pathogenic (PMID: 19777577). This variant is present in population databases (rs386833747, gnomAD 0.003%). Disruption of this splice site has been observed in individual(s) with Meckel-Gruber syndrome (PMID: 19777577). ClinVar contains an entry for this variant (Variation ID: 56299). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic.

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.32

BayesDel_noAF

Pathogenic

0.30

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

Eigen

Pathogenic

1.2

Eigen_PC

Pathogenic

1.0

FATHMM_MKL

Pathogenic

1.0

PhyloP100

8.9

GERP RS

5.6

Mutation Taster

=0/100

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.94

SpliceAI score (max)

0.95

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.95

Position offset: -1

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

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over