rs386833747

Variant names:

• chr4-15553306-G-A
• rs386833747
• NM_001378615.1:c.2486+1G>A

Your query was ambiguous. Multiple possible variants found:

• chr4-15553306-G-A
• chr4-15553306-G-C

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001378615.1(CC2D2A):​c.2486+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000151 in 1,459,370 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: not found (cov: 32)
  • Exomes 𝑓: 0.000015 (0 hom.)
• Consequence: CC2D2A NM_001378615.1 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 8.93
• Publications: 3 publications found

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

ACMG classification

Our verdict: Pathogenic. The variant received 12 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-A is Pathogenic according to our data. Variant chr4-15553306-G-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2931771.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CC2D2A	NM_001378615.1	c.2486+1G>A		splice_donor_variant, intron_variant	Intron 19 of 36	ENST00000424120.6	NP_001365544.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CC2D2A	ENST00000424120.6	c.2486+1G>A		splice_donor_variant, intron_variant	Intron 19 of 36	5	NM_001378615.1	ENSP00000403465.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.0000151 AC: 22 AN: 1459370 Hom.: 0 Cov.: 31 AF XY: 0.0000152 AC XY: 11 AN XY: 725842

African (AFR) AF: 0.00 AC: 0 AN: 33348

American (AMR) AF: 0.00 AC: 0 AN: 44376

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26102

East Asian (EAS) AF: 0.00 AC: 0 AN: 39572

South Asian (SAS) AF: 0.00 AC: 0 AN: 85578

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53350

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.0000171 AC: 19 AN: 1111000

Other (OTH) AF: 0.0000498 AC: 3 AN: 60278

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000826 Hom.: 1

Bravo AF: 0.0000113

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Meckel-Gruber syndrome;C0431399:Joubert syndrome Pathogenic:1

Sep 20, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. Disruption of this splice site has been observed in individual(s) with Meckel-Gruber syndrome (PMID: 19777577). This variant is not present in population databases (gnomAD no frequency). 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). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.37
CADD	Pathogenic	32
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	1.0	D
PhyloP100		8.9
GERP RS		5.6
Mutation Taster		=0/100	disease causing

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

Other links and lift over

dbSNP: rs386833747; hg19: chr4-15554929;