rs878854168

Variant names:

• chr4-15596207-G-A
• rs878854168
• NM_001378615.1:c.4437G>A

Your query was ambiguous. Multiple possible variants found:

• chr4-15596207-G-A
• chr4-15596207-G-C
• chr4-15596207-G-T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_001378615.1(CC2D2A):​c.4437G>A​(p.Gln1479Gln) variant causes a splice region, synonymous change. The variant allele was found at a frequency of 0.000000737 in 1,357,608 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 7.4e-7 (0 hom.)
• Consequence: CC2D2A NM_001378615.1 splice_region, synonymous
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.38
• Publications: 0 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: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CC2D2A	NM_001378615.1	c.4437G>A	p.Gln1479Gln	splice_region_variant, synonymous_variant	Exon 34 of 37	ENST00000424120.6	NP_001365544.1
CC2D2A	NM_001080522.2	c.4437G>A	p.Gln1479Gln	splice_region_variant, synonymous_variant	Exon 35 of 38		NP_001073991.2
CC2D2A	NM_001378617.1	c.4290G>A	p.Gln1430Gln	splice_region_variant, synonymous_variant	Exon 32 of 35		NP_001365546.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CC2D2A	ENST00000424120.6	c.4437G>A	p.Gln1479Gln	splice_region_variant, synonymous_variant	Exon 34 of 37	5	NM_001378615.1	ENSP00000403465.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 7.37e-7 AC: 1 AN: 1357608 Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0 AN XY: 668050

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

African (AFR) AF: 0.00 AC: 0 AN: 29398

American (AMR) AF: 0.00 AC: 0 AN: 27822

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 23532

East Asian (EAS) AF: 0.00 AC: 0 AN: 35236

South Asian (SAS) AF: 0.00 AC: 0 AN: 71090

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 48048

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4754

European-Non Finnish (NFE) AF: 9.42e-7 AC: 1 AN: 1061636

Other (OTH) AF: 0.00 AC: 0 AN: 56092

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Oct 13, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects codon 1479 of the CC2D2A mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the CC2D2A protein. This variant also falls at the last nucleotide of exon 35, which is part of the consensus splice site for this exon. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. 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. ClinVar contains an entry for this variant (Variation ID: 1023694). This variant has not been reported in the literature in individuals affected with CC2D2A-related conditions. This variant is not present in population databases (gnomAD no frequency). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.36
CADD	Benign	22
DANN	Benign	0.85
PhyloP100		6.4

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	1.0
SpliceAI score (max)		0.91		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.91		Position offset: 0

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

Other links and lift over

dbSNP: rs878854168; hg19: chr4-15597830;