rs386833759

chr4-15580170-CAGTA-C

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PVS1_Moderate PM2 PP3 PP5_Very_Strong

The NM_001378615.1(CC2D2A):c.3975+4_3975+7del variant causes a splice donor, splice donor region, coding sequence, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,609,986 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 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: CC2D2A NM_001378615.1 splice_donor, splice_donor_region, coding_sequence, intron
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 9.38

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]

ACMG classification

Verdict is Pathogenic. Variant got 13 ACMG points.

• PVS1: Splicing variant, NOT destroyed by nmd, known LOF gene, truncates exone, which is 0.04174378 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 4-15580170-CAGTA-C is Pathogenic according to our data. Variant chr4-15580170-CAGTA-C is described in ClinVar as [Pathogenic]. Clinvar id is 217617.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr4-15580170-CAGTA-C is described in Lovd as [Pathogenic]. Variant chr4-15580170-CAGTA-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CC2D2A	NM_001378615.1	c.3975+4_3975+7del		splice_donor_variant, splice_donor_region_variant, coding_sequence_variant, intron_variant	30/37	ENST00000424120.6
CC2D2A	NM_001080522.2	c.3975+4_3975+7del		splice_donor_variant, splice_donor_region_variant, coding_sequence_variant, intron_variant	31/38
CC2D2A	NM_001378617.1	c.3828+4_3828+7del		splice_donor_variant, splice_donor_region_variant, coding_sequence_variant, intron_variant	28/35

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CC2D2A	ENST00000424120.6	c.3975+4_3975+7del		splice_donor_variant, splice_donor_region_variant, coding_sequence_variant, intron_variant	30/37	5	NM_001378615.1	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152182 Hom.: 0 Cov.: 32

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1457804 Hom.: 0 AF XY: 0.00000138 AC XY: 1 AN XY: 725432

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000271

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152182 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74354

Gnomad4 AFR AF: 0.00

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: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Meckel-Gruber syndrome;C0431399:Familial aplasia of the vermis Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jan 22, 2024

This sequence change falls in intron 31 of the CC2D2A gene. It does not directly change the encoded amino acid sequence of the CC2D2A protein. It affects a nucleotide within the consensus splice site. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individual(s) with clinical features of Joubert syndrome (PMID: 19466712, 26092869, 29146704; Invitae). 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.3975delA+1_3delGTA. ClinVar contains an entry for this variant (Variation ID: 217617). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). 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. -

Meckel syndrome, type 6 Pathogenic:1

Likely pathogenic, no assertion criteria provided

literature only

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

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Joubert syndrome 9 Pathogenic:1

Pathogenic, criteria provided, single submitter

research

UW Hindbrain Malformation Research Program, University of Washington

Feb 23, 2015

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Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.73		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.73		Position offset: 1

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

Publications

LitVar

Other links and lift over

dbSNP: rs386833759; hg19: chr4-15581793;