rs386833760

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1_ModeratePP5_Very_Strong

The NM_001378615.1(CC2D2A):​c.4179+1delG variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000767 in 1,578,048 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.00018 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000065 ( 0 hom. )

Consequence

CC2D2A
NM_001378615.1 splice_donor, intron

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:13

Conservation

PhyloP100: 8.11

Publications

4 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 10 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.023442319 fraction of the gene. Cryptic splice site detected, with MaxEntScore 5.1, offset of -1, new splice context is: tgaGTaaga. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
PP5
Variant 4-15587928-AG-A is Pathogenic according to our data. Variant chr4-15587928-AG-A is described in ClinVar as Pathogenic. ClinVar VariationId is 56312.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
CC2D2ANM_001378615.1 linkc.4179+1delG splice_donor_variant, intron_variant Intron 32 of 36 ENST00000424120.6 NP_001365544.1
CC2D2ANM_001080522.2 linkc.4179+1delG splice_donor_variant, intron_variant Intron 33 of 37 NP_001073991.2 Q9P2K1-4
CC2D2ANM_001378617.1 linkc.4032+1delG splice_donor_variant, intron_variant Intron 30 of 34 NP_001365546.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CC2D2AENST00000424120.6 linkc.4179+1delG splice_donor_variant, intron_variant Intron 32 of 36 5 NM_001378615.1 ENSP00000403465.1 Q9P2K1-4

Frequencies

GnomAD3 genomes
AF:
0.000184
AC:
28
AN:
152138
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00118
Gnomad ASJ
AF:
0.00173
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000588
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000931
AC:
23
AN:
247170
AF XY:
0.0000969
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000294
Gnomad ASJ exome
AF:
0.000902
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000891
Gnomad OTH exome
AF:
0.000503
GnomAD4 exome
AF:
0.0000652
AC:
93
AN:
1425792
Hom.:
0
Cov.:
24
AF XY:
0.0000661
AC XY:
47
AN XY:
711328
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32664
American (AMR)
AF:
0.000180
AC:
8
AN:
44446
Ashkenazi Jewish (ASJ)
AF:
0.000929
AC:
24
AN:
25828
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39506
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85102
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53280
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5684
European-Non Finnish (NFE)
AF:
0.0000528
AC:
57
AN:
1080184
Other (OTH)
AF:
0.0000677
AC:
4
AN:
59098
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.491
Heterozygous variant carriers
0
5
10
14
19
24
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.000184
AC:
28
AN:
152256
Hom.:
0
Cov.:
31
AF XY:
0.000295
AC XY:
22
AN XY:
74458
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41532
American (AMR)
AF:
0.00118
AC:
18
AN:
15298
Ashkenazi Jewish (ASJ)
AF:
0.00173
AC:
6
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000588
AC:
4
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.529
Heterozygous variant carriers
0
1
3
4
6
7
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000565
Hom.:
0
Bravo
AF:
0.000283

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:13
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Meckel syndrome, type 6 Pathogenic:3
-
Juha Muilu Group; Institute for Molecular Medicine Finland (FIMM)
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

-
Juha Muilu Group; Institute for Molecular Medicine Finland (FIMM)
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Jan 29, 2024
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.4179+1delG is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Three predict the variant abolishes a canonical 5' splicing donor site, and two predict the variant creates a cryptic 5' donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 9.3e-05 in 247170 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in CC2D2A causing Meckel Syndrome Type 6 (9.3e-05 vs 0.0011), allowing no conclusion about variant significance. c.4179+1delG has been reported in the literature in individuals affected with Meckel Syndrome or Joubert Syndrome (Mougou-Zerelli_2009, Tallila_2009, Bachmann-Gagescu_2015). These data indicate that the variant is likely to be associated with disease. The following publications have been ascertained in the context of this evaluation (PMID: 19777577, 19466712, 26092869). ClinVar contains an entry for this variant (Variation ID: 56312). Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided Pathogenic:2
Mar 14, 2016
Eurofins Ntd Llc (ga)
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Apr 27, 2022
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Canonical splice site variant expected to result in aberrant splicing, although in the absence of functional evidence the actual effect of this sequence change is unknown.; This variant is associated with the following publications: (PMID: 31589614, 33486889, 19777577, 26092869, 19466712) -

Joubert syndrome 9 Pathogenic:2
Feb 23, 2015
UW Hindbrain Malformation Research Program, University of Washington
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

- -

Jan 01, 2016
Centre for Mendelian Genomics, University Medical Centre Ljubljana
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was classified as: Pathogenic. The following ACMG criteria were applied in classifying this variant: PVS1,PS1,PM2,PP4. -

Joubert syndrome 9;C2676790:Meckel syndrome, type 6;C5436837:COACH syndrome 2;C5676970:Retinitis pigmentosa 93 Pathogenic:1
Apr 03, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Pathogenic:1
Dec 16, 2021
Ambry Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.4179+1delG variant results from a deletion of one nucleotide at position c.4179+1 and involves the canonical splice donor site after coding exon 31 of the CC2D2A gene. Alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. Based on data from gnomAD, the - allele has an overall frequency of 0.01% (23/247170) total alleles studied. The highest observed frequency was 0.09% (9/9980) of Ashkenazi Jewish alleles. This mutation has been identified in 2 compound heterozygous individuals with Joubert syndrome as well as 2 compound heterozygous fetuses with Meckel syndrome (Mougou-Zerelli, 2009; Tallila, 2009; Bachmann-Gagescu, 2015). Based on the available evidence, this alteration is classified as pathogenic. -

Clubfoot;C0022680:Polycystic kidney disease;C0079924:Oligohydramnios;C0426790:Narrow chest;C4282400:Polydactyly, postaxial, type A1;C4551563:Microcephaly;C4551722:Encephalocele Pathogenic:1
Jan 01, 2017
Centre for Mendelian Genomics, University Medical Centre Ljubljana
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Meckel-Gruber syndrome Pathogenic:1
Sep 22, 2014
Genetic Services Laboratory, University of Chicago
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Meckel-Gruber syndrome;C0431399:Joubert syndrome Pathogenic:1
Sep 19, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change affects a splice site in intron 33 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 (rs386833761, gnomAD 0.09%). Disruption of this splice site has been observed in individual(s) with Joubert and/or Meckel-Gruber syndrome (PMID: 19777577, 26092869). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is also known as c.4179del. ClinVar contains an entry for this variant (Variation ID: 56312). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Anencephaly;C0152427:Polydactyly;C3887499:Renal cyst Pathogenic:1
May 12, 2021
Genetics Institute, Tel Aviv Sourasky Medical Center
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
8.1
Mutation Taster
=5/195
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.83
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.83
Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs386833760; hg19: chr4-15589551; API